This document summarizes Fermat's little theorem and discusses primitive roots modulo n. It states that if p is a prime number, then for any integer a, ap-1 ≡ 1 (mod p). It then defines a primitive root modulo n as a number g such that g generates all numbers from 1 to n-1 when raised to successive powers modulo n. The document provides an example of a primitive root modulo 11 and discusses how primitive roots relate to permutations.
This document summarizes Fermat's little theorem and discusses primitive roots modulo n. It states that if p is a prime number, then for any integer a, ap-1 ≡ 1 (mod p). It then defines a primitive root modulo n as a number g such that g generates all numbers from 1 to n-1 when raised to successive powers modulo n. The document provides an example of a primitive root modulo 11 and discusses how primitive roots relate to permutations.
Conditional expectation projection 2018 feb 18 HanpenRobot
The document discusses conditional expectation and orthogonal projection in an inner product space L2. It defines the inner product of random variables X and Y in L2 as their expected value E(XY). It also states that for a subspace L2G of L2, the conditional expectation E(Y|G) is the orthogonal projection of Y onto L2G, and that the expected value of X(Y - E(Y|G)) is 0.
The Laplace transform exhibits a property of duality where the Laplace transform of the nth derivative of a function f(t) is equal to (-1)^n times the nth derivative of the Laplace transform of f(t) with respect to s. This property allows derivatives in the time domain to correspond to derivatives in the frequency domain. As an example, the Laplace transform of t^-3 * e^(-ct) is shown to equal 6/(s+c)^4 by applying this duality property.
The document discusses conjugate cyclic permutations in group theory. It defines a cyclic permutation τ as a bijection from a set of numbers n to itself, where it maps n to n and a number k to the number following it. It then defines the conjugate of a cyclic permutation τ by another cyclic permutation τ-1 as mapping the elements i1, i2, ..., ir of τ to their images under τ-1 in the same order. So the conjugate of τ by τ-1 is obtained by applying τ-1 to each element of τ.
The document discusses the derivative of a quadratic form Q(x) = xTAx. It shows that the gradient of Q(x) is equal to 2Ax. To find the saddle point of Q(x), the derivative with respect to x, which is 2Ax, is set equal to 0. Solving this results in an expression for the coordinates x and y of the saddle point in terms of the coefficients of the quadratic form matrix A.
This document discusses diagonalizing a 2x2 matrix A. It shows that if vλ1 and vλ2 are eigenvectors of A, then expressing a vector in the coordinate system of vλ1 and vλ2 results in the matrix being equal to a diagonal matrix with the eigenvalues λ1 and λ2 on the diagonal.
This document finds the representation matrix of the derivative operator on a 2-dimensional vector space over the complex numbers, with basis vectors e^αt and te^αt. It shows that applying the derivative to the basis vectors results in (x1α + x2)e^αt + αx2te^αt. Therefore, the representation matrix of the derivative is α 1 0 α.
Conditional expectation projection 2018 feb 18 HanpenRobot
The document discusses conditional expectation and orthogonal projection in an inner product space L2. It defines the inner product of random variables X and Y in L2 as their expected value E(XY). It also states that for a subspace L2G of L2, the conditional expectation E(Y|G) is the orthogonal projection of Y onto L2G, and that the expected value of X(Y - E(Y|G)) is 0.
The Laplace transform exhibits a property of duality where the Laplace transform of the nth derivative of a function f(t) is equal to (-1)^n times the nth derivative of the Laplace transform of f(t) with respect to s. This property allows derivatives in the time domain to correspond to derivatives in the frequency domain. As an example, the Laplace transform of t^-3 * e^(-ct) is shown to equal 6/(s+c)^4 by applying this duality property.
The document discusses conjugate cyclic permutations in group theory. It defines a cyclic permutation τ as a bijection from a set of numbers n to itself, where it maps n to n and a number k to the number following it. It then defines the conjugate of a cyclic permutation τ by another cyclic permutation τ-1 as mapping the elements i1, i2, ..., ir of τ to their images under τ-1 in the same order. So the conjugate of τ by τ-1 is obtained by applying τ-1 to each element of τ.
The document discusses the derivative of a quadratic form Q(x) = xTAx. It shows that the gradient of Q(x) is equal to 2Ax. To find the saddle point of Q(x), the derivative with respect to x, which is 2Ax, is set equal to 0. Solving this results in an expression for the coordinates x and y of the saddle point in terms of the coefficients of the quadratic form matrix A.
This document discusses diagonalizing a 2x2 matrix A. It shows that if vλ1 and vλ2 are eigenvectors of A, then expressing a vector in the coordinate system of vλ1 and vλ2 results in the matrix being equal to a diagonal matrix with the eigenvalues λ1 and λ2 on the diagonal.
This document finds the representation matrix of the derivative operator on a 2-dimensional vector space over the complex numbers, with basis vectors e^αt and te^αt. It shows that applying the derivative to the basis vectors results in (x1α + x2)e^αt + αx2te^αt. Therefore, the representation matrix of the derivative is α 1 0 α.