This document provides solutions to homework problems from a complex analysis course. It analyzes the differentiability of several complex functions by checking if they satisfy the Cauchy-Riemann equations. For differentiable functions, it computes their derivatives according to the Cauchy-Riemann theorem. The solutions involve defining real and imaginary parts of functions, taking partial derivatives, and applying limits.
1. The document provides solutions to homework problems from a complex analysis class.
2. It shows the work to find harmonic conjugates and derivatives of complex functions, evaluate complex expressions, and take logarithms and exponents of complex numbers.
3. Key steps include using the Cauchy-Riemann equations to test if functions are analytic, decomposing complex expressions into polar form, and applying properties of logarithms and exponents to manipulate expressions.
The document discusses solving the two-dimensional Laplace equation to model steady heat flow problems. It presents:
1) The general boundary value problem (BVP) for the Laplace equation in a semi-infinite and finite lamina.
2) The separation of variables method to obtain solutions as a sum of products of ordinary differential equations.
3) Applying boundary conditions to determine constants and obtain the general solution for temperature distribution.
4) Examples of applying the method to specific BVPs for steady heat flow, including plates with various boundary temperature profiles and geometries.
1. This document contains 20 multiple part questions about differential equations. The questions cover topics like determining the degree and order of differential equations, solving differential equations, identifying whether equations are homogeneous, and forming differential equations to represent families of curves with given properties.
2. The questions range from 1 to 6 marks and include both conceptual questions about differential equations as well as problems requiring solving specific equations. A variety of solution techniques are required including separating variables, homogeneous property, and identifying particular solutions given initial conditions.
3. The document tests mastery of fundamental differential equation concepts and skills like classification, solving, identifying homogeneous property, and setting up equations to model geometric situations. A solid understanding of differential equations is needed to successfully answer all
Complex analysis and differential equationSpringer
This document introduces holomorphic functions and some of their key properties. It begins by defining limits, continuity, differentiability, and holomorphic functions. It then introduces the Cauchy-Riemann equations, which provide a necessary condition for differentiability involving the partial derivatives of the real and imaginary parts. Several examples are provided to illustrate these concepts. The document also discusses properties of derivatives of holomorphic functions and proves that differentiability implies continuity. It concludes by defining connected sets.
1. The document contains an assignment on mathematics involving ordinary and partial differential equations, matrices, vector calculus, and their applications. It includes solving various types of differential equations, finding eigenvectors and eigenvalues of matrices, evaluating line, surface and volume integrals using Green's theorem and Stokes' theorem. The assignment contains 20 problems spanning these topics.
2. The assignment covers key concepts in differential equations, linear algebra, and vector calculus including solving ordinary differential equations, partial differential equations, systems of linear equations, eigenproblems, line integrals, surface integrals, divergence, curl, gradient, Laplacian, and theorems like Green's theorem and Stokes' theorem.
3. Students are required to solve 20 problems involving these
This document contains an exercise set with 46 problems involving real numbers, intervals, and inequalities. The problems cover topics such as determining whether numbers are rational or irrational, solving equations, graphing inequalities on number lines, factoring polynomials, and solving compound inequalities.
The document discusses complex differentiability and analytic functions. It shows that for a function f(z) to be complex differentiable, the Cauchy-Riemann equations relating the partial derivatives of the real and imaginary parts must be satisfied. It also discusses representing functions as power series and their radii of convergence. Multivalued functions like logarithms and roots are discussed, noting the need for branch cuts to define single-valued branches.
1. The document contains examples of evaluating limits as the variable approaches certain values.
2. Several limits were found to be indeterminate forms that require further algebraic manipulation to find the limit.
3. Key observations were made about the behavior of functions as the variable approaches values like noticing a function approaches a certain value as the variable nears another value.
1. The document provides solutions to homework problems from a complex analysis class.
2. It shows the work to find harmonic conjugates and derivatives of complex functions, evaluate complex expressions, and take logarithms and exponents of complex numbers.
3. Key steps include using the Cauchy-Riemann equations to test if functions are analytic, decomposing complex expressions into polar form, and applying properties of logarithms and exponents to manipulate expressions.
The document discusses solving the two-dimensional Laplace equation to model steady heat flow problems. It presents:
1) The general boundary value problem (BVP) for the Laplace equation in a semi-infinite and finite lamina.
2) The separation of variables method to obtain solutions as a sum of products of ordinary differential equations.
3) Applying boundary conditions to determine constants and obtain the general solution for temperature distribution.
4) Examples of applying the method to specific BVPs for steady heat flow, including plates with various boundary temperature profiles and geometries.
1. This document contains 20 multiple part questions about differential equations. The questions cover topics like determining the degree and order of differential equations, solving differential equations, identifying whether equations are homogeneous, and forming differential equations to represent families of curves with given properties.
2. The questions range from 1 to 6 marks and include both conceptual questions about differential equations as well as problems requiring solving specific equations. A variety of solution techniques are required including separating variables, homogeneous property, and identifying particular solutions given initial conditions.
3. The document tests mastery of fundamental differential equation concepts and skills like classification, solving, identifying homogeneous property, and setting up equations to model geometric situations. A solid understanding of differential equations is needed to successfully answer all
Complex analysis and differential equationSpringer
This document introduces holomorphic functions and some of their key properties. It begins by defining limits, continuity, differentiability, and holomorphic functions. It then introduces the Cauchy-Riemann equations, which provide a necessary condition for differentiability involving the partial derivatives of the real and imaginary parts. Several examples are provided to illustrate these concepts. The document also discusses properties of derivatives of holomorphic functions and proves that differentiability implies continuity. It concludes by defining connected sets.
1. The document contains an assignment on mathematics involving ordinary and partial differential equations, matrices, vector calculus, and their applications. It includes solving various types of differential equations, finding eigenvectors and eigenvalues of matrices, evaluating line, surface and volume integrals using Green's theorem and Stokes' theorem. The assignment contains 20 problems spanning these topics.
2. The assignment covers key concepts in differential equations, linear algebra, and vector calculus including solving ordinary differential equations, partial differential equations, systems of linear equations, eigenproblems, line integrals, surface integrals, divergence, curl, gradient, Laplacian, and theorems like Green's theorem and Stokes' theorem.
3. Students are required to solve 20 problems involving these
This document contains an exercise set with 46 problems involving real numbers, intervals, and inequalities. The problems cover topics such as determining whether numbers are rational or irrational, solving equations, graphing inequalities on number lines, factoring polynomials, and solving compound inequalities.
The document discusses complex differentiability and analytic functions. It shows that for a function f(z) to be complex differentiable, the Cauchy-Riemann equations relating the partial derivatives of the real and imaginary parts must be satisfied. It also discusses representing functions as power series and their radii of convergence. Multivalued functions like logarithms and roots are discussed, noting the need for branch cuts to define single-valued branches.
1. The document contains examples of evaluating limits as the variable approaches certain values.
2. Several limits were found to be indeterminate forms that require further algebraic manipulation to find the limit.
3. Key observations were made about the behavior of functions as the variable approaches values like noticing a function approaches a certain value as the variable nears another value.
1) The document provides solutions to homework problems from a complex analysis course. It solves problems involving properties of polynomials, including showing two polynomials are equal if they have the same roots, and investigating properties of roots.
2) It also analyzes singularities of complex functions, determining whether singularities are removable, poles, or essential singularities. Functions include rational, trigonometric, exponential and combined functions.
3) The solutions demonstrate techniques for analyzing complex functions at isolated singular points using principles like series expansions and the Casorati-Weierstrass theorem.
The document defines proper and improper integrals, and discusses different types of improper integrals based on whether the limits are infinite or the function is unbounded. It provides tests to determine if improper integrals converge or diverge, including the T1 test involving exponential functions, the T2 test involving power functions, and comparison tests. Examples are worked through applying these tests to determine if various improper integrals converge or diverge. The key information is on defining improper integrals and tests to analyze their convergence.
This document provides examples of transformations involving complex variables and their applications. It contains 3 examples of inversion transformations where a line or circle in the z-plane is transformed to a circle or line in the w-plane. It also contains 2 examples of square transformations where a region in the z-plane is transformed to parabolic regions in the w-plane. Additionally, it discusses finding the image of a line or circle under translations in the complex plane.
This document provides information on formulas and properties related to quadratic equations and complex numbers. It defines key terms like quadratic expression, quadratic equation, nature of roots, conjugate roots, and symmetric functions of roots. It also covers finding the sum and product of roots, forming an equation given roots, and locating roots. Properties of complex numbers such as representation, powers of i, modulus, argument, and square roots are described. De Moivre's theorem relating powers of complex numbers to trigonometric functions is also summarized.
The document discusses addition and multiplication of matrices. It provides examples of adding two matrices of the same order, as well as multiplying a matrix by a scalar value. Key points include:
- To add matrices, corresponding elements are added if the matrices are the same order
- Multiplying a matrix by a scalar involves multiplying each element of the matrix by the scalar value
- Examples are provided to demonstrate calculating the sum and product of matrices step-by-step
This document provides lecture notes on complex analysis covering four units of content:
1) The index of a close curve, Cauchy's theorem, and entire functions.
2) Counting zeroes, meromorphic functions, and maximum principle.
3) Spaces of continuous and analytic functions, and behavior of functions.
4) Comparison of entire functions, analytic continuation, and harmonic functions.
It also provides definitions and theorems regarding integrals over rectifiable curves, winding numbers, and Cauchy's theorem. Exercises and proofs are included.
1. The document provides 14 problems involving partial differential equations (PDEs). The problems involve forming PDEs by eliminating arbitrary constants from functions, finding complete integrals, and solving PDEs.
2. Methods used include taking partial derivatives, finding auxiliary equations, and making substitutions to isolate the PDE or solve it.
3. The document covers a range of techniques for working with PDEs, including eliminating constants, finding trial solutions, integrating subsidiary equations, and solving auxiliary equations to find complete integrals.
This document provides information about the theoretical physics course Phys2325 at the University of Hong Kong, including the course code, homepage, lecturer contact information, textbook, contents covered, and assessment details. The course covers complex variables and their applications in theoretical physics, including Cauchy's integral formula, properties of special functions, Fourier series, and solutions to partial differential equations. Students will be assessed through one 3-hour written exam worth 80% and a course assessment worth 20% of the final grade.
This document discusses solving a differential equation using the Frobenius method. It presents the equation xy'' + (1 - 2x)y' + (x - 1)y = 0 and provides steps to find the indicial equation and power series solutions. These include determining coefficients, setting coefficients of like powers of x equal to 0, and solving the resulting equations to obtain the solutions as a power series expansion in terms of x.
This document contains a large collection of mathematical expressions, equations, and sets. Some key points:
- It includes expressions like n(A), n(B), n[(A-B)(B-A)], and n(A × B) with various values.
- There are several equations set equal to values, such as x2 - 3x < 0, -2 < log < -1, and equations containing sums, integrals, and logarithms.
- Sets are defined containing various elements like numbers, vectors, and functions.
Demoivre's theorem states that for any value of n (positive, negative, integer or fractional), the value of (cosθ + i sinθ)n is equal to cos(nθ) + i sin(nθ).
The theorem is proved by considering three cases: when n is a positive integer using mathematical induction, when n is a negative integer by relating it to the positive case, and when n is a fraction by relating it to the integer case.
The theorem has various applications including finding the nth roots of complex numbers. To find the nth root of a complex number z expressed in polar form as (cosθ + i sinθ)r, we take the nth power of both sides using
1) The document discusses second order linear differential equations with constant or variable coefficients.
2) It provides the general form of second order linear differential equations and various methods to solve them including reduction of order, finding independent solutions, and using the characteristic equation.
3) The methods are demonstrated on examples of homogeneous differential equations with constant coefficients, including cases where the roots of the characteristic equation are real, repeated, or complex.
Solution Manual : Chapter - 02 Limits and ContinuityHareem Aslam
This document contains solutions to exercise sets on limits and continuity from a textbook. Exercise Set 2.1 contains solutions to 23 problems evaluating limits of functions as the input values approach certain numbers. Exercise Set 2.2 contains solutions to 38 similar problems evaluating limits. Exercise Set 2.3 contains solutions to 23 additional limit evaluation problems. The document provides the step-by-step workings and conclusions for each problem.
This document contains the solutions to 5 questions related to calculus concepts like integration, derivatives, series approximation, and geometry of curves and surfaces. Some of the key steps include:
- Using integration to find volumes, masses, and centroids
- Finding critical points and classifying extrema
- Approximating a series to evaluate an integral
- Solving a geometric series problem to find an initial height
- Analyzing motion problems using kinematic equations
- Finding equations of planes and tangent lines to surfaces
This document contains exercises related to inverse functions and their properties. It includes 53 multi-part exercises involving determining if functions are inverses, composing functions, finding inverse functions, and evaluating derivatives of inverse functions. The exercises involve algebraic manipulation and graphical analysis of functions and their inverses.
1. This section introduces substitution methods for exact differential equations. It provides examples of homogeneous differential equations and their solutions obtained through substitutions that transform the equations into separable form.
2. Fifteen problems walk through specific substitution methods and solutions for homogeneous differential equations. Additional examples demonstrate substitutions that transform Bernoulli equations into linear equations.
3. Examples of optional material on airplane flight trajectories are included, as well as substitution methods and solutions for additional differential equation problems.
1. The document introduces complex numbers and some basic results regarding complex numbers such as the complex conjugate and modulus of a complex number.
2. It then discusses functions of a complex variable, defining a complex function and its Cartesian and polar forms. It also covers continuity, derivatives, and analytic functions of a complex variable.
3. The Cauchy-Riemann equations are derived and provide a necessary condition for a function to be analytic (differentiable everywhere in a neighborhood). Two examples are provided to illustrate the Cauchy-Riemann equations and analytic functions.
This document provides solutions to problems from a complex analysis homework assignment. The solutions involve applying theorems related to contour integrals, Cauchy's integral formula, and derivatives to evaluate definite integrals over curves and find derivatives of functions. Key steps include using the Cauchy-Goursat theorem when functions are analytic over regions, and applying Cauchy's integral formula and its generalization to derivatives to evaluate integrals that involve singularities inside curves.
This section introduces differential equations and their use in mathematical modeling. It provides examples of verifying solutions to differential equations by direct substitution. Typical problems show finding an integrating constant to satisfy an initial condition. Differential equations are derived from descriptions of real-world phenomena involving rates of change. The section establishes foundational knowledge of differential equations and their solution methods.
The Solovay-Kitaev Theorem guarantees that for any single-qubit gate U and precision ε > 0, it is possible to approximate U to within ε using Θ(logc(1/ε)) gates from a fixed finite universal set of quantum gates. The proof involves first using a "shrinking lemma" to show that any gate in an ε-net can be approximated to within Cε using a constant number of applications of gates from the universal set. This is then iterated to construct an approximation of the desired gate U to arbitrary precision using a number of gates that scales as the logarithm of 1/ε.
This document provides solutions to exercises from a complex analysis homework assignment. It includes:
1) Computing powers and roots of complex numbers using polar forms and identities
2) Sketching and describing properties of sets involving complex quantities like openness, boundedness, and being a domain
3) Finding and sketching images of complex mappings
1) The document provides solutions to homework problems from a complex analysis course. It solves problems involving properties of polynomials, including showing two polynomials are equal if they have the same roots, and investigating properties of roots.
2) It also analyzes singularities of complex functions, determining whether singularities are removable, poles, or essential singularities. Functions include rational, trigonometric, exponential and combined functions.
3) The solutions demonstrate techniques for analyzing complex functions at isolated singular points using principles like series expansions and the Casorati-Weierstrass theorem.
The document defines proper and improper integrals, and discusses different types of improper integrals based on whether the limits are infinite or the function is unbounded. It provides tests to determine if improper integrals converge or diverge, including the T1 test involving exponential functions, the T2 test involving power functions, and comparison tests. Examples are worked through applying these tests to determine if various improper integrals converge or diverge. The key information is on defining improper integrals and tests to analyze their convergence.
This document provides examples of transformations involving complex variables and their applications. It contains 3 examples of inversion transformations where a line or circle in the z-plane is transformed to a circle or line in the w-plane. It also contains 2 examples of square transformations where a region in the z-plane is transformed to parabolic regions in the w-plane. Additionally, it discusses finding the image of a line or circle under translations in the complex plane.
This document provides information on formulas and properties related to quadratic equations and complex numbers. It defines key terms like quadratic expression, quadratic equation, nature of roots, conjugate roots, and symmetric functions of roots. It also covers finding the sum and product of roots, forming an equation given roots, and locating roots. Properties of complex numbers such as representation, powers of i, modulus, argument, and square roots are described. De Moivre's theorem relating powers of complex numbers to trigonometric functions is also summarized.
The document discusses addition and multiplication of matrices. It provides examples of adding two matrices of the same order, as well as multiplying a matrix by a scalar value. Key points include:
- To add matrices, corresponding elements are added if the matrices are the same order
- Multiplying a matrix by a scalar involves multiplying each element of the matrix by the scalar value
- Examples are provided to demonstrate calculating the sum and product of matrices step-by-step
This document provides lecture notes on complex analysis covering four units of content:
1) The index of a close curve, Cauchy's theorem, and entire functions.
2) Counting zeroes, meromorphic functions, and maximum principle.
3) Spaces of continuous and analytic functions, and behavior of functions.
4) Comparison of entire functions, analytic continuation, and harmonic functions.
It also provides definitions and theorems regarding integrals over rectifiable curves, winding numbers, and Cauchy's theorem. Exercises and proofs are included.
1. The document provides 14 problems involving partial differential equations (PDEs). The problems involve forming PDEs by eliminating arbitrary constants from functions, finding complete integrals, and solving PDEs.
2. Methods used include taking partial derivatives, finding auxiliary equations, and making substitutions to isolate the PDE or solve it.
3. The document covers a range of techniques for working with PDEs, including eliminating constants, finding trial solutions, integrating subsidiary equations, and solving auxiliary equations to find complete integrals.
This document provides information about the theoretical physics course Phys2325 at the University of Hong Kong, including the course code, homepage, lecturer contact information, textbook, contents covered, and assessment details. The course covers complex variables and their applications in theoretical physics, including Cauchy's integral formula, properties of special functions, Fourier series, and solutions to partial differential equations. Students will be assessed through one 3-hour written exam worth 80% and a course assessment worth 20% of the final grade.
This document discusses solving a differential equation using the Frobenius method. It presents the equation xy'' + (1 - 2x)y' + (x - 1)y = 0 and provides steps to find the indicial equation and power series solutions. These include determining coefficients, setting coefficients of like powers of x equal to 0, and solving the resulting equations to obtain the solutions as a power series expansion in terms of x.
This document contains a large collection of mathematical expressions, equations, and sets. Some key points:
- It includes expressions like n(A), n(B), n[(A-B)(B-A)], and n(A × B) with various values.
- There are several equations set equal to values, such as x2 - 3x < 0, -2 < log < -1, and equations containing sums, integrals, and logarithms.
- Sets are defined containing various elements like numbers, vectors, and functions.
Demoivre's theorem states that for any value of n (positive, negative, integer or fractional), the value of (cosθ + i sinθ)n is equal to cos(nθ) + i sin(nθ).
The theorem is proved by considering three cases: when n is a positive integer using mathematical induction, when n is a negative integer by relating it to the positive case, and when n is a fraction by relating it to the integer case.
The theorem has various applications including finding the nth roots of complex numbers. To find the nth root of a complex number z expressed in polar form as (cosθ + i sinθ)r, we take the nth power of both sides using
1) The document discusses second order linear differential equations with constant or variable coefficients.
2) It provides the general form of second order linear differential equations and various methods to solve them including reduction of order, finding independent solutions, and using the characteristic equation.
3) The methods are demonstrated on examples of homogeneous differential equations with constant coefficients, including cases where the roots of the characteristic equation are real, repeated, or complex.
Solution Manual : Chapter - 02 Limits and ContinuityHareem Aslam
This document contains solutions to exercise sets on limits and continuity from a textbook. Exercise Set 2.1 contains solutions to 23 problems evaluating limits of functions as the input values approach certain numbers. Exercise Set 2.2 contains solutions to 38 similar problems evaluating limits. Exercise Set 2.3 contains solutions to 23 additional limit evaluation problems. The document provides the step-by-step workings and conclusions for each problem.
This document contains the solutions to 5 questions related to calculus concepts like integration, derivatives, series approximation, and geometry of curves and surfaces. Some of the key steps include:
- Using integration to find volumes, masses, and centroids
- Finding critical points and classifying extrema
- Approximating a series to evaluate an integral
- Solving a geometric series problem to find an initial height
- Analyzing motion problems using kinematic equations
- Finding equations of planes and tangent lines to surfaces
This document contains exercises related to inverse functions and their properties. It includes 53 multi-part exercises involving determining if functions are inverses, composing functions, finding inverse functions, and evaluating derivatives of inverse functions. The exercises involve algebraic manipulation and graphical analysis of functions and their inverses.
1. This section introduces substitution methods for exact differential equations. It provides examples of homogeneous differential equations and their solutions obtained through substitutions that transform the equations into separable form.
2. Fifteen problems walk through specific substitution methods and solutions for homogeneous differential equations. Additional examples demonstrate substitutions that transform Bernoulli equations into linear equations.
3. Examples of optional material on airplane flight trajectories are included, as well as substitution methods and solutions for additional differential equation problems.
1. The document introduces complex numbers and some basic results regarding complex numbers such as the complex conjugate and modulus of a complex number.
2. It then discusses functions of a complex variable, defining a complex function and its Cartesian and polar forms. It also covers continuity, derivatives, and analytic functions of a complex variable.
3. The Cauchy-Riemann equations are derived and provide a necessary condition for a function to be analytic (differentiable everywhere in a neighborhood). Two examples are provided to illustrate the Cauchy-Riemann equations and analytic functions.
This document provides solutions to problems from a complex analysis homework assignment. The solutions involve applying theorems related to contour integrals, Cauchy's integral formula, and derivatives to evaluate definite integrals over curves and find derivatives of functions. Key steps include using the Cauchy-Goursat theorem when functions are analytic over regions, and applying Cauchy's integral formula and its generalization to derivatives to evaluate integrals that involve singularities inside curves.
This section introduces differential equations and their use in mathematical modeling. It provides examples of verifying solutions to differential equations by direct substitution. Typical problems show finding an integrating constant to satisfy an initial condition. Differential equations are derived from descriptions of real-world phenomena involving rates of change. The section establishes foundational knowledge of differential equations and their solution methods.
The Solovay-Kitaev Theorem guarantees that for any single-qubit gate U and precision ε > 0, it is possible to approximate U to within ε using Θ(logc(1/ε)) gates from a fixed finite universal set of quantum gates. The proof involves first using a "shrinking lemma" to show that any gate in an ε-net can be approximated to within Cε using a constant number of applications of gates from the universal set. This is then iterated to construct an approximation of the desired gate U to arbitrary precision using a number of gates that scales as the logarithm of 1/ε.
This document provides solutions to exercises from a complex analysis homework assignment. It includes:
1) Computing powers and roots of complex numbers using polar forms and identities
2) Sketching and describing properties of sets involving complex quantities like openness, boundedness, and being a domain
3) Finding and sketching images of complex mappings
The document discusses polynomials and their properties. It defines zeros of a polynomial as numbers that make the polynomial equal to 0 when substituted in. It provides examples of finding zeros and using the remainder and factor theorems. It also covers factorizing polynomials using identities and splitting the middle term. Key polynomial identities are presented along with examples of expanding and factorizing polynomial expressions.
The document presents solutions to 6 problems:
1) Finding the maximum area of a quadrilateral inscribed in a circle.
2) Proving that 30 divides the difference of two prime number sets with differences of 8.
3) Showing polynomials with integer coefficients satisfy a recursive relation.
4) Determining the number of points dividing a triangle into equal area triangles.
5) Proving an acute triangle is equilateral given conditions on angle bisectors and altitudes.
6) Characterizing a function on integers satisfying two properties.
This document discusses differentiable and analytic functions of a complex variable z. It defines the derivative of a complex function f(z) and shows that for f(z) to be differentiable, the Cauchy-Riemann equations relating the partial derivatives of the real and imaginary parts must be satisfied. Examples are provided to illustrate calculating derivatives and determining differentiability. The document also covers power series representations of functions, elementary functions like exponential and logarithmic functions, and the concepts of branch points and cuts for multi-valued complex functions.
1. The document discusses various types of transformations in complex analysis, including translation, rotation, stretching, and inversion.
2. Under inversion (1/w=z), a straight line is mapped to a circle if it does not pass through the origin, and to another straight line if it does pass through the origin. A circle is always mapped to another circle.
3. A general bilinear or Möbius transformation can be expressed as a combination of translation, rotation, stretching, and inversion.
This document provides solutions to problems from Chapter 2 and Chapter 3 of the book "Partial Differential Equations" by Lawrence C. Evans. The solutions include:
1) Finding an explicit formula for a function satisfying a given PDE.
2) Showing that the Laplacian of a transformed function equals the Laplacian of the original function.
3) Modifying the mean value property for harmonic functions to account for functions satisfying -Δu = f.
Let f(z) be a function continuous at a point z0.
To show that f(z) is also continuous at z0, we need to show:
limz→z0 f(z) = f(z0)
Since f(z) is given to be continuous at z0, by the definition of continuity:
limz→z0 f(z) = f(z0)
Therefore, if f(z) is continuous at a point z0, it automatically satisfies the condition for continuity at z0. Hence, f(z) is also continuous at z0.
So in summary, if a function f(z) is continuous at a
The document provides solutions to problems from an IIT-JEE 2004 mathematics exam. Problem 1 asks the student to find the center and radius of a circle defined by a complex number relation. The solution shows that the center is the midpoint of points dividing the join of the constants in the ratio k:1, and gives the radius. Problem 2 asks the student to prove an inequality relating dot products of four vectors satisfying certain conditions. The solution shows that the vectors must be parallel or antiparallel.
1. The document discusses algebraic principles for multiplying and factorizing sums and differences of numbers. It introduces the formula (a + b)(c + d) = ac + ad + bc + bd for multiplying two sums, and similar formulas for multiplying sums and differences.
2. It then applies these formulas to derive algebraic identities for the square of a sum, the difference of squares, and the product of a sum and difference. Examples are provided to demonstrate how these identities can be used to simplify calculations.
3. Readers are prompted with examples to practice applying the different algebraic formulas and identities introduced in the document.
This document provides information about a theoretical physics course, including the course code, homepage, lecturer contact information, textbook, main topics covered, and assessment details. The course covers complex variables and their applications in theoretical physics. Topics include Cauchy's integral formula, calculus of residues, partial differential equations, special functions, and Fourier series. Students will be assessed through a 3-hour written exam worth 80% and a course assessment worth 20%.
Triangle ABC is given, with altitudes CD and BE from vertices C and B to opposite sides AB and AC respectively being equal. It is proved that triangle ABC must be isosceles by showing that triangles CBD and BCE are congruent by the right angle-hypotenuse (RHS) criterion, implying corresponding angles are equal, and then using corresponding parts of congruent triangles to show sides AB and AC are equal, making triangle ABC isosceles.
The document discusses Gauss Divergence Theorem and provides two examples of using it to evaluate surface integrals. Gauss Divergence Theorem states that the surface integral of a vector field F over a closed surface S enclosing a volume V is equal to the volume integral of the divergence of F over V. The first example uses this to evaluate a surface integral over a cylinder. The second example verifies Gauss Divergence Theorem for a vector field F over the surface of a cube.
The document provides solutions to questions from an IIT-JEE mathematics exam. It includes 8 questions worth 2 marks each, 8 questions worth 4 marks each, and 2 questions worth 6 marks each. The solutions solve problems related to probability, trigonometry, geometry, calculus, and loci. The summary focuses on the high-level structure and content of the document.
1. The point of inflection of the function y = x3 − 3x2 + 6x + 2000 is x = 1. At this point, the slope is 3.
2. The optimal length for Karen to climb is when x = √3/3, which is the solution to the equation 1 − 3x2 = 0 derived from finding the critical points of her change in position, x − x3.
3. By applying the Fundamental Theorem of Calculus, the constant C in the solution to the given integral 1/4π ∫0 sin x + C dx is equal to 2√2 − 4/π.
1) Implicit differentiation is a method for finding the slope of a curve when the equation is given implicitly rather than explicitly as y = f(x).
2) Examples are given of implicitly defined curves like circles, ellipses, and a 4-leaf clover curve.
3) The process of implicit differentiation takes the derivative of both sides of the implicit equation and solves for the derivative dy/dx.
This document defines the function f(x) = 3√(x)/√(|x| + 1) and provides exercises to analyze properties of the function including its domain, limits, continuity, derivatives, critical numbers, points of inflection, asymptotes, and sketching its graph. The exercises require computing limits, derivatives, critical numbers, points of inflection, and asymptotes then using these to draw the graph of the defined function.
This document defines the function f(x) = 3√(x)/(x^2-1) and provides 8 exercises to analyze properties of the function: (1) find the domain, (2) compute limits as x approaches positive/negative infinity, (3) compute derivatives, (4) find critical numbers and points of inflection, (5) find asymptotes, and (6) draw the graph of the function.
This document contains exercises to prove properties of the function f(x) = 1/(x^2+1). The first exercise shows that f(x) = -x^2/(x^2+1)(f(x)+1) for all real numbers x. The second exercise shows that 0 < f(x)+1 ≤ 1 for all real x. The third exercise uses the epsilon-delta definition of limits to show that the limit of f(x) as x approaches 0 equals 1.
This document contains solutions to homework problems from a complex analysis course. It solves problems involving logarithms, exponentials, trigonometric and hyperbolic functions of complex numbers. Key steps and solutions are shown for problems involving contour integrals of complex functions along curves in the complex plane. The length of one such curve is computed to be 8a. Several contour integrals are evaluated, with one found to be equal to 1 - i. Bounds on contour integrals are also determined using theorems.
This document contains solutions to problems from a complex analysis homework assignment. Problem 21.2 involves determining the convergence of several series using tests from Chapter 21. Problem 21.4 examines the sum of a geometric series. Subsequent problems analyze the pointwise and uniform convergence of series and determine radii of convergence using tests such as the Ratio Test and Cauchy-Hadamard formula.
This document provides solutions to homework problems from a complex analysis course. It solves problems involving properties of complex numbers, Cauchy's inequality, roots of unity, and proving that if the roots of a polynomial equation satisfy a certain condition, then the roots must all be real. The solutions demonstrate algebraic manipulations and reasoning about complex numbers and functions.
The simplified electron and muon model, Oscillating Spacetime: The Foundation...RitikBhardwaj56
Discover the Simplified Electron and Muon Model: A New Wave-Based Approach to Understanding Particles delves into a groundbreaking theory that presents electrons and muons as rotating soliton waves within oscillating spacetime. Geared towards students, researchers, and science buffs, this book breaks down complex ideas into simple explanations. It covers topics such as electron waves, temporal dynamics, and the implications of this model on particle physics. With clear illustrations and easy-to-follow explanations, readers will gain a new outlook on the universe's fundamental nature.
How to Manage Your Lost Opportunities in Odoo 17 CRMCeline George
Odoo 17 CRM allows us to track why we lose sales opportunities with "Lost Reasons." This helps analyze our sales process and identify areas for improvement. Here's how to configure lost reasons in Odoo 17 CRM
How to Fix the Import Error in the Odoo 17Celine George
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9
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How to Build a Module in Odoo 17 Using the Scaffold Method
Hw2sol
1. NCU Math, Spring 2014: Complex Analysis Homework Solution 2
Text Book: An Introduction to Complex Analysis
Problem. 7.3
Sol:
(a)
f(z) = u(x, y) + iv(x, y) where we dene u(x, y) = x and v(x, y) = −y2
. It is easy to see that u and v are
smooth. So we have
∂u
∂x = 1, ∂u
∂y = 0,
∂v
∂x = 0, ∂v
∂y = −2y.
Since ∂u
∂y = −∂v
∂x = 0 and ∂u
∂x = ∂v
∂y = 1 i y = −1
2 , we can get that f(z) is dierentiable only at y = −1
2 and is
not dierentiable at z = −1
2 by virtue of Theorem 6.4 and 6.5. Moreover, f (z) = ∂u
∂x (0, −1
2 ) + i∂v
∂x (0, −1
2 ) = 1 for
z = −1
2 by Theorem 6.5.
(b)
f(z) = u(x, y)+iv(x, y) where we dene u(x, y) = x2
and v(x, y) = y2
. It is easy to see that u and v are smooth.
So we have
∂u
∂x = 2x, ∂u
∂y = 0,
∂v
∂x = 0, ∂v
∂y = 2y.
Since ∂u
∂y = −∂v
∂x = 0 and ∂u
∂x = ∂v
∂y = 2x = 2y i x = y, we can get that f(z) is dierentiable only at x = y and is not
dierentiable at z ∈ {x + iy|x = y} by virtue of Theorem 6.4 and 6.5. Moreover, f (z) = ∂u
∂x (x, x) + i∂v
∂x (x, x) = 2x
for z = x + ix and x ∈ R by Theorem 6.5.
(c)
f(z) = u(x, y)+iv(x, y) where we dene u(x, y) = yx and v(x, y) = y2
. It is easy to see that u and v are smooth.
So we have
∂u
∂x = y, ∂u
∂y = x,
∂v
∂x = 0, ∂v
∂y = 2y.
Since ∂u
∂x = ∂v
∂y and ∂u
∂y = −∂v
∂x i x = y = 0, we can get that f(z) is dierentiable only at x = y = 0 and
is not dierentiable at z ∈ {x + iy|x = 0 or y = 0} by virtue of Theorem 6.4 and 6.5. Moreover, f (z) =
∂u
∂x (0, 0) + i∂v
∂x (0, 0) = 0 for z = 0 by Theorem 6.5.
(d)
1
2. f(z) = u(x, y) + iv(x, y) where we dene u(x, y) = x3
and v(x, y) = (1 − y)3
. It is easy to see that u and v are
smooth. So we have
∂u
∂x = 3x2
, ∂u
∂y = 0,
∂v
∂x = 0, ∂v
∂y = −3(1 − y)2
.
Since ∂u
∂y = −∂v
∂x = 0 and ∂u
∂x = ∂v
∂y = 3x2
= −3(1−y)2
= 0 i x = 0 and y = 1, we can get that f(z) is dierentiable
only at x = 0, y = 1 and is not dierentiable at z ∈ {x + iy|x = 0 or y = 1} by virtue of Theorem 6.4 and 6.5.
Moreover, f (z) = ∂u
∂x (0, 1) + i∂v
∂x (0, 1) = 0 for z = i by Theorem 6.5.
Problem. 7.4
Sol:
(a)
We dene u(x, y) = x3
+ 3xy2
− 3x and v(x, y) = y3
+ 3x2
y − 3y. So f(z) = u + iv. It is easy to see that u and
v are smooth. So we have
∂u
∂x = 3x2
+ 3y2
− 3, ∂u
∂y = 6xy,
∂v
∂x = 6xy, ∂v
∂y = 3y2
+ 3x2
− 3.
Since ∂u
∂x = ∂v
∂y = 3x2
+ 3y2
− 3 and ∂u
∂y = −∂v
∂x i xy = 0 , we can get that f(z) is dierentiable only at xy = 0 and
is not dierentiable at z ∈ {x + iy|xy = 0} by virtue of Theorem 6.4 and 6.5. Thus f is not analytic everywhere.
Moreover, f (z) = ∂u
∂x (x, y) + i∂v
∂x (x, y) = 3x2
− 3 or 3y2
− 3 for z = x or iy by Theorem 6.5.
(b)
From some computations,
f(z) = 6(x2
− y2
− 2xyi) − 2(x − yi) − 4i(x2
+ y2
)
= (6x2
− 6y2
− 2x) + i(−4x2
− 4y2
− 12xy + 2y).
We dene u(x, y) = 6x2
− 6y2
− 2x and v(x, y) = −4x2
− 4y2
− 12xy + 2y. So f(z) = u + iv. It is easy to see that
u and v are smooth. So we have
∂u
∂x = 12x − 2, ∂u
∂y = −12y,
∂v
∂x = −8x − 12y, ∂v
∂y = −8y − 12x + 2.
Then
∂u
∂x
=
∂v
∂y
⇔ 6x + 2y = 1,
∂u
∂y
= −
∂v
∂x
⇔ x + 3y = 0.
This implies that ∂u
∂x = ∂v
∂y and ∂u
∂y = −∂v
∂x i z = 3
16 − 1
16 i. Thus we can get that f(z) is dierentiable only at
z = 3
16 − 1
16 i and is not dierentiable at z ∈ C − { 3
16 − 1
16 i} by virtue of Theorem 6.4 and 6.5. Therefore f is not
analytic everywhere. Moreover, f ( 3
16 − 1
16 i) = ∂u
∂x ( 3
16 , − 1
16 ) + i∂v
∂x ( 3
16 , − 1
16 ) = 1
4 − 3
4 i by Theorem 6.5.
2
3. (c)
We dene u(x, y) = 3x2
+ 2x − 3y2
− 1 and v(x, y) = 6xy + 2y. So f(z) = u + iv. It is easy to see that u and v
are smooth. So we have
∂u
∂x = 6x + 2, ∂u
∂y = −6y,
∂v
∂x = 6y, ∂v
∂y = 6x + 2.
Since ∂u
∂x = ∂v
∂y = 6x + 2 and ∂u
∂y = −∂v
∂x = −6y for all z ∈ C , we can get that f(z) is dierentiable for all z ∈ C by
virtue of Theorem 6.4 and 6.5. Thus f is analytic in C. Moreover, f (z) = ∂u
∂x (x, y)+i∂v
∂x (x, y) = 6x+2+6yi = 6z+2
for z ∈ C by Theorem 6.5.
(d)
Since f doesn't dene in z = 0, ±2i, we only consider z ∈ C − {0, ±2i}. By virtue of Theorem 6.1, we have
f(z) = 2z2
+6
z(z2+4) is dierentiable for all z ∈ C − {0, ±2i}. f is not analytic in C but is analytic in C − {0, ±2i}. When
we use Theorem 6.1 again, we can get that
f (z) =
4z(z(z2
+ 4)) − (2z2
+ 6)(3z2
+ 4)
(z(z2 + 4))
2
=
−2(z4
+ 5z2
+ 12)
z2(z2 + 4)2
.
for all z ∈ C − {0, ±2i}.
(e)
It is easy to see that
f(z) = ey2
−x2
e−2xyi
= e−(x2
+2xyi−y2
)
= e−z2
.
Since −z2
, ez
are dierentiable in C and Theorem 6.1, we can get that f(z) = e−z2
is dierentiable in C. So f is
analytic in C. Moreover,
f (z) = e−z2
· (−2z)
= −2ze−z2
by virtue of Theorem 6.1 and Example 7.1.
Problem. 7.5
Sol:
3
4. Since
w(z) = (ay3
+ ix3
) + xy(bx + icy)
= (ay3
+ bx2
y) + i(x3
+ cxy2
),
we dene u(x, y) = ay3
+ bx2
y and v(x, y) = x3
+ cxy2
. It is easy to see that u and v are smooth and
∂u
∂x = 2bxy, ∂u
∂y = 3ay2
+ bx2
,
∂v
∂x = 3x2
+ cy2
, ∂v
∂y = 2cxy.
So w is analytic i
∂u
∂x = ∂v
∂y ,
∂u
∂y = −∂v
∂x ,
⇔
2bxy = 2cxy,
3ay2
+ bx2
= −(3x2
+ cy2
),
from Theorem 6.4 and 6.5. This implies that w is analytic i a = 1 and b = c = −3. Moreover, we have
∂w
∂z
=
∂u
∂x
+ i
∂v
∂x
= −6xy + i(3x2
− 3y2
)
= 3i(x2
+ 2ixy − y2
)
= 3i · z2
by Theorem 6.5.
Problem. 7.8
Sol:
(a)
It is easy to see that
f(z) =
z2
z if z = 0,
0 if z = 0,
=
z3
|z|2 if z = 0,
0 if z = 0,
=
x3
−3xy2
x2+y2 + i−3x2
y+y3
x2+y2 if z = 0,
0 if z = 0,
= u(x, y) + iv(x, y)
4
5. where we dene
u(x, y) =
0 if x = y = 0
x3
−3xy2
x2+y2 o.w.
and v(x, y) =
0 if x = y = 0
−3x2
y+y3
x2+y2 o.w.
So
∂u
∂x
(0, 0) = lim
h→0
h3
−3h·02
h2+02 − 0
h
= lim
h→0
h
h
= 1,
∂u
∂y
(0, 0) = lim
k→0
03
−3·0·k2
02+k2 − 0
k
= lim
h→0
0
k
= 0,
∂v
∂x
(0, 0) = lim
h→0
−3h2
·0+03
h2+02 − 0
h
= lim
h→0
0
h
= 0,
∂v
∂y
(0, 0) = lim
k→0
−3·02
k+k3
02+k2 − 0
k
= lim
h→0
k
h
= 1.
This implies that ∂u
∂x (0, 0) = ∂v
∂y (0, 0) = 1 and ∂u
∂y (0, 0) = −∂v
∂x (0, 0) = 0. Thus f satises Cauchy-Riemann equations
at z = 0.
(b)
From some computations, we have for z = 0
f(z) − f(0)
z
=
z2
z
z
=
z
z
2
.
It suces to show that limz→0
z
z
2
doesn't exist. It is easy to see that
lim
z=x,x→0
z
z
2
= lim
z=x→0
x
x
2
= 1.
Also
lim
z=x+ix,x→0
z
z
2
= lim
z=x+ix,x→0
x − ix
x + ix
2
= lim
z=x+ix,x→0
1 − i
1 + i
2
=
1 − i
1 + i
2
=
(1 − i)4
4
.
Since 1 = (1−i)4
4 , we can get that limz→0
z
z
2
doesn't exist.
5
6. Problem. 7.10
Sol:
Since x = r cos θ and y = r sin θ, we can get that
∂x
∂r
= cos θ,
∂x
∂θ
= −r sin θ,
∂y
∂r
= sin θ,
∂y
∂θ
= r cos θ.
By chain rule, we have
∂u
∂r
=
∂u
∂x
·
∂x
∂r
+
∂u
∂y
·
∂y
∂r
=
∂u
∂x
cos θ +
∂u
∂y
sin θ,
∂u
∂θ
=
∂u
∂x
·
∂x
∂θ
+
∂u
∂y
·
∂y
∂θ
= r(−
∂u
∂x
sin θ +
∂u
∂y
cos θ),
∂v
∂r
=
∂v
∂x
·
∂x
∂r
+
∂v
∂y
·
∂y
∂r
=
∂v
∂x
cos θ +
∂v
∂y
sin θ,
∂v
∂θ
=
∂v
∂x
·
∂x
∂θ
+
∂v
∂y
·
∂y
∂θ
= r(−
∂v
∂x
sin θ +
∂v
∂y
cos θ).
So
∂u
∂r
=
∂v
∂y
cos θ −
∂v
∂x
sin θ =
1
r
∂v
∂θ
,
∂u
∂θ
= r(−
∂v
∂y
sin θ −
∂v
∂x
cos θ) = −r
∂v
∂r
.
by virtue of Cauchy-Riemann conditions.
Conversely, we have
∂r
∂x
=
x
r
,
∂r
∂y
=
y
r
,
∂θ
∂x
=
−y
r2
,
∂θ
∂y
=
x
r2
,
6
7. from r2
= x2
+ y2
and θ = tan−1
(y
x ). Since chain rule, we can get that
∂u
∂x
=
∂u
∂r
·
∂r
∂x
+
∂u
∂θ
·
∂θ
∂x
=
∂u
∂r
x
r
−
∂u
∂θ
y
r2
,
∂u
∂y
=
∂u
∂r
·
∂r
∂y
+
∂u
∂θ
·
∂θ
∂y
=
∂u
∂r
y
r
+
∂u
∂θ
x
r2
,
∂v
∂x
=
∂v
∂r
·
∂r
∂x
+
∂v
∂θ
·
∂θ
∂x
=
∂v
∂r
x
r
−
∂v
∂θ
y
r2
,
∂v
∂y
=
∂v
∂r
·
∂r
∂y
+
∂v
∂θ
·
∂θ
∂y
=
∂v
∂r
y
r
+
∂v
∂θ
x
r2
.
Thus
∂u
∂x
=
∂v
∂θ
x
r2
+
∂v
∂r
y
r
=
∂v
∂y
,
∂u
∂y
=
∂v
∂θ
y
r2
−
∂v
∂r
x
r
= −
∂v
∂x
,
by (7.7).
Moreover,
f (z) =
∂u
∂x
+ i
∂v
∂x
= (
∂u
∂r
x
r
−
∂u
∂θ
y
r2
) + i(
∂v
∂r
x
r
−
∂v
∂θ
y
r2
)
= (
∂u
∂r
x
r
+
∂v
∂r
y
r
) + i(
∂v
∂r
x
r
−
∂u
∂r
y
r
)
= (cos θ − i sin θ)ur + (sin θ + i cos θ)vr
= e−iθ
ur + ie−iθ
vr
= e−iθ
(ur + ivr).
from above, Theorem 6.5, and (7.7).
We dene u(r, θ) =
√
r cos θ
2 and v(r, θ) =
√
r sin θ
2 . Then f(z) =
√
re−iθ/2
=
√
r cos θ
2 + i
√
r sin θ
2 = u(r, θ) +
iv(r, θ). Obviously, u and v are smooth in C − {0}. Also,
∂u
∂r = 1
2
√
r
cos θ
2 , ∂u
∂θ = −
√
r
2 sin θ
2 ,
∂v
∂r = 1
2
√
r
sin θ
2 , ∂v
∂θ =
√
r
2 cos θ
2 ,
for all z ∈ C − {0}. So
∂u
∂r
=
1
2
√
r
cos
θ
2
=
1
r
∂v
∂θ
,
∂u
∂θ
=
−
√
r
2
sin
θ
2
= −r
∂v
∂r
.
7
8. Thus we can apply Theorem 6.5 to get that f(z) is dierentiable at all z except z = 0. Moreover, we have
f (z) = e−iθ
(ur + ivr)
= e−iθ
(
1
2
√
r
cos
θ
2
+ i
1
2
√
r
sin
θ
2
)
=
1
2
√
r
e−iθ
e
iθ
2
=
1
2
√
r
e− iθ
2 .
Problem. 7.18
Sol:
(a)
Since ∂2
u
∂x2 = e−x
sin y and ∂2
u
∂y2 = −e−x
sin y are both smooth, we have ∂2
u
∂x2 + ∂2
u
∂y2 = 0. So u is harmonic.
Let v(x, y) satises that ∂v
∂y = ∂u
∂x = −e−x
sin y and ∂v
∂x = −∂u
∂y = −e−x
cos y. Then v = e−x
cos y +h(x) for some
real-valued function h by ∂v
∂y = −e−x
sin y. But ∂v
∂x = −e−x
cos y. So h (x) = 0. This implies that v = e−x
cos y + C
for some real constant C. Thus the corresponding analytic function is e−x
sin y + ie−x
cos y + iC for some real
constant C.
(b)
Since ∂2
v
∂x2 = − cos x cosh y and ∂2
u
∂y2 = cos x cosh y are both smooth, we have ∂2
u
∂x2 + ∂2
u
∂y2 = 0. So u is harmonic.
Let u(x, y) satises that ∂u
∂x = ∂v
∂y = cos x sinh y and ∂u
∂y = −∂v
∂x = sin x cosh y. Then u = sin x sinh y + h(y)
for some real-valued function h by ∂u
∂x = cos x sinh y. But ∂u
∂y = sin x cosh y. So h (y) = 0. This implies that u =
sin x sinh y +C for some real constant C. Thus the corresponding analytic function is sin x sinh y +C +i cos x cosh y
for some real constant C.
Problem. 7.24
Sol:
For convenience, we dene C = {(x, y)|u(x, y) = c} and D = {(x, y)|v(x, y) = d}. Let (a, b) ∈ C ∩ D with
f (a+ib) = 0. Since (a, b) ∈ C and f (a+ib) = 0, the tangent vector to C at (a, b) is parallel to (uy(a, b), −ux(a, b)) =
0. Similarly, we have the tangent vector to D at (a, b) is parallel to (vy(a, b), −vx(a, b)) = 0. It suces to show that
(uy(a, b), −ux(a, b)) · (vy(a, b), −vx(a, b)) = 0. Because of Cauchy-Riemann equations, we can get that
(uy(a, b), −ux(a, b)) · (vy(a, b), −vx(a, b))
=uy(a, b)vy(a, b) + ux(a, b) · vx(a, b)
= − vx(a, b)ux(a, b) + ux(a, b) · vx(a, b)
=0.
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9. Now, we consider the case f(z) = z2
= (x2
− y2
) + 2xyi. So C = {(x, y)|x2
− y2
= c} and D = {(x, y)|2xy = d}.
Let (a, b) ∈ C ∩ D with f (a + ib) = 0. Thus a2
= b2
and ab = 0. The tangent vector to C at (a, b) is parallel to
(b, a) = 0. Similarly, The tangent vector to D at (a, b) is parallel to (a, −b) = 0. Then C and D are orthogonal by
(b.a) · (a, −b) = 0.
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