Topic: CONIC SECTION, POLAR COORDINATES AND SPACE GEOMETRY



CONIC SECTION




Ax2 + By2 + Dx + Ey + F = 0 is the general equation of conics


CIRCLE
Circle is set points which lie at a fixed distance called the                Circle Tangent to Line Ax + By + C = 0
radius and from a fixed point called the center




Standard equation: r 2 = (x − h)2 + (y − k)2                                       | Ah + Bk + C |
         Where: r=radius                                                     r =
                (h, k) = center of the circle                                           A 2 + B2
                (x, y) = any point in the circle
                                                                             General equation of a circle:              x 2 + y 2 + Dx + Ey + F = 0
                                                                                                     where D, E and F are arbitrary constants.
                                                                                         NOTE:       r 2 < 0 no graph (imaginary circle)
                                                                                                     r 2 = 0 graph is a single point
                                                                                                     r 2 > 0 graph is a circle



PARABOLA
The locus of a moving point that its distance from a fixed point called the focus is equal to its distance from a fixed line called the
directrix.



                                                                             Where: F = focus
                                                                                    v = vertex, midpoint of the segment
                                                                                    d1 = d2
                                                                                    e = eccentricity = 1




Standard equation:          (y − k)2 = 4a (x − h)        if the directrix is vertical
                                   2
                            (x − h) = 4a (y − k)         if the directrix is horizontal

Various opening of a parabola




General equation of a parabola: x2 + Dx + Ey + F = 0               is a parabola with horizontal directrix

                                       y2 + Dx + Ey + F = 0        is a parabola with vertical directrix.


   DAY 7                                                 Copyright 2010                                                www.e-reviewonline.com
Topic: CONIC SECTION, POLAR COORDINATES AND SPACE GEOMETRY



ELLIPSE
An ellipse is a set of points in a plane, such that the sum of the distances of each from two fixed point is a constant. The fixed points
are called the foci and the line through them is the axis.



                                                                              Where: F1, F2 = focus
                                                                                     v1, v2 = vertex, midpoint of the segment
                                                                                     d1 + d2 = 2a
                                                                                                         d    c
                                                                                     e = eccentricity = 3 = < 1
                                                                                                         d4   a
                                                                                             a
                                                                                        d=
                                                                                             e
                                                                                        a2 = b 2 + c 2
                                                                                                               2b 2
                                                                                       LR = Latus Rectum =
                                                                                                                a




                            (x − h)2       (y − k)2
Standard equation:              2
                                       +              =1   if the major axis, M.A. is parallel to the x-axis
                              a              b2

                            (y − k)2       (x − h)2
                                  2
                                       +              =1   if the major axis, M.A. is parallel to the y-axis
                              a              b2

General equation of an ellipse: Ax 2 + By 2 + Dx + Ey + F = 0 where A and B is greater than 0
         NOTE:    M < 0 no graph (imaginary ellipse)
                  M = 0 graph is a single point
                  M > 0 graph is an ellipse
                                       D2   E2
                           M = −F +       +
                                       4A 4B

HYPERBOLA
A hyperbola is a set of points in a plane, such that the difference of the distances of each from two fixed point is a constant. The
fixed points are called the foci and the line through them is the axis.



                                                                              Where: F1, F2 = focus
                                                                                     v1, v2 = vertex, midpoint of the segment
                                                                                     d1 + d2 = 2a
                                                                                                         d    c
                                                                                     e = eccentricity = 3 =     >1
                                                                                                         d4   a
                                                                                             a
                                                                                        d=
                                                                                             e
                                                                                        c 2 =a2 +b 2
                                                                                                               2b 2
                                                                                       LR = Latus Rectum =
                                                                                                                a



Equation of Asymptote
       Asymptote of a curve is a line when the perpendicular distance from a line to a curve approaches zero as the curve extends
       indefinitely far from the origin.

                  y − k = ±m(x − h)

         Where (h, k) is the center of the hyperbola and m is the slope, m=b/a if the axis is horizontal and m=a/b if the axis is
         vertical. Use (+) for upward asymptote and (-) for downward asymptote.

                            (x − h)2       (y − k)2
Standard equation:                     −              =1   if the transverse axis is parallel to the x-axis (Opens left and right)
                               a2             b2

                            (y − k)2       (x − h)2
                                  2
                                       −              =1   if the transverse axis is parallel to the y-axis (Opens up and down)
                               a              b2

         Length of transverse axis (TA) = 2a
         Length of conjugate axis (CA) = 2b
         Length of the focal axis (FA) = 2c

General equation of hyperbola: Ax 2 + By 2 + Dx + Ey + F = 0 where A or B is less than 0




   DAY 7                                                   Copyright 2010                                         www.e-reviewonline.com
Topic: CONIC SECTION, POLAR COORDINATES AND SPACE GEOMETRY




POLAR COORDINATES
The coordinates of a point in a plane are its distance from a              Relationship between Rectangular and Polar
fixed point and its direction from a fixed line.                           Coordinates




Where: r = radius vector or modulus
       θ = amplitude or argument or vectorial angle




                                                                           x = r cos θ                  r =    x2 + y2
                                                                                                                     y
                                                                           y = r sin θ                  θ = tan −1
                                                                                                                     x


Curve Tracing on Polar Coordinates
   1. The graph of r=k, where k is a constant and greater                      4.    The graph of r 2 = a2 sin 2θ or r 2 = a2 cos 2θ is a
       than 0 (k>0) is a circle with center at the pole.                             lemniscate.
       Illustration:                                                                 Illustration:
                 r=2
                                                                                                r 2 = 4 sin 2θ




    2.   The graph of r = 2a sin θ , c(a,90o) and r=|a| or
         r = 2a cos θ , c(a, 0o) and r=|a| is a circle that
         passes through the pole.
         Illustration:
                                                                                              r 2 = 3 cos 2θ
                    r = 4 sin θ




                   r = 4 cos θ

                                                                               5.    The graph of r = a sin(nθ) or r = a cos(nθ) is an n-
                                                                                     leaved rose
                                                                                               If n is an odd integer, then it is a n-leaved
                                                                                               rose
                                                                                               If n is an even integer, it is a 2n-leaved rose
                                                                                               If n = 1, then there is one petal and it is
                                                                                               circular
                                                                                     Illustration:
    3.   The graph of r = a(1 ± sin θ) or r = a(1 ± cos θ) is a                                 r = 3 sin 4θ
         cardiod.
         Illustration:
                    r = 3(1 − cos θ)




                                                                                              r = 2 cos 2θ


                   r = 1 − cos θ




   DAY 7                                                  Copyright 2010                                         www.e-reviewonline.com
Topic: CONIC SECTION, POLAR COORDINATES AND SPACE GEOMETRY




    6.   The graph of r = a ± b sin θ or r = a ± b cos θ is a limacon.
                   If |a| < |b| the graph is a limacon with inner loop
                   If |a| = |b| the graph is a cardiod
                   If |a| > |b| the graph is a limacon without a loop
         Illustration:
                    r = 1 − 2 cos θ                                              r = 4 + sin θ




SPACE GEOMETRY
Three Dimensional Coordinate System
                                                   Distance formula in three space                        Distance between a point (x, y, z)
                                                                                                          and a plane

                                                                                                                        Ax 1 + By 1 + Cz 1 + D
                                                                                                                   d=
                                                                                                                            A 2 + B2 + C2

                                                                                                          Midpoint formula
                                                                                                                      x + x2
                                                                                                                  x = 1
                                                                                                                         2
                                                                                                                      y1 + y 2
                                                                                                                  y =
                                                                                                                         2
                                                                                                                      z1 + z 2
                                                                                                                  z=
                                                                                                                         2
Cartesian coordinates (x, y z)                      d = (x 2 − x 1 )2 + (y 2 − y 1 )2 + (z 2 − z1 )2




Plane

The graph of Ax + By + Cz = D is a plane
Illustration:                                                                    Cylinders
                                                                                           Any equation in two variables, represents a
Graph: 2x + y + 3z = 6                                                                     cylindrical surface, that is perpendicular to the two
                                                                                           variables and whose generating curve is the plane
                                                                                           curve whose equation is given.
                                                                                 Illustration:

                                                                                 Graph: x2+z2=4




Sphere:
Standard equation: (x − h)2 + (y − k)2 + (z − l)2 = r 2
General equation: x 2 + y 2 + z 2 + Dx + Ey + Fz + G = 0

Illustration:
Graph: x 2 + y 2 + z 2 − 2x + 4y + 6z − 2 = 0                                    Graph: y2=4x
         C(1,-2,3) and r = 4




   DAY 7                                                   Copyright 2010                                            www.e-reviewonline.com
Topic: CONIC SECTION, POLAR COORDINATES AND SPACE GEOMETRY




Quadratic Surfaces

   1.   Ellipsoid                                                   3.   Hyperboloid of Two Sheets




                    x2       y2          z2
                     2
                         +       2
                                     +        =1
                    a        b           c2

   2.   Hyperboloid of One Sheet                                                   x2       y2          z2
                                                                                    2
                                                                                        −       2
                                                                                                    −        =1
                                                                                   a        b           c2

                                                                    4.   Elliptic Paraboloid




                    x2       y2          z2
                     2
                         +       2
                                     −        =1
                    a        b           c2



                                                                                   x2       y2
                                                                                    2
                                                                                        −           =z
                                                                                   a        b2




  DAY 7                                            Copyright 2010                                             www.e-reviewonline.com

Day 07

  • 1.
    Topic: CONIC SECTION,POLAR COORDINATES AND SPACE GEOMETRY CONIC SECTION Ax2 + By2 + Dx + Ey + F = 0 is the general equation of conics CIRCLE Circle is set points which lie at a fixed distance called the Circle Tangent to Line Ax + By + C = 0 radius and from a fixed point called the center Standard equation: r 2 = (x − h)2 + (y − k)2 | Ah + Bk + C | Where: r=radius r = (h, k) = center of the circle A 2 + B2 (x, y) = any point in the circle General equation of a circle: x 2 + y 2 + Dx + Ey + F = 0 where D, E and F are arbitrary constants. NOTE: r 2 < 0 no graph (imaginary circle) r 2 = 0 graph is a single point r 2 > 0 graph is a circle PARABOLA The locus of a moving point that its distance from a fixed point called the focus is equal to its distance from a fixed line called the directrix. Where: F = focus v = vertex, midpoint of the segment d1 = d2 e = eccentricity = 1 Standard equation: (y − k)2 = 4a (x − h) if the directrix is vertical 2 (x − h) = 4a (y − k) if the directrix is horizontal Various opening of a parabola General equation of a parabola: x2 + Dx + Ey + F = 0 is a parabola with horizontal directrix y2 + Dx + Ey + F = 0 is a parabola with vertical directrix. DAY 7 Copyright 2010 www.e-reviewonline.com
  • 2.
    Topic: CONIC SECTION,POLAR COORDINATES AND SPACE GEOMETRY ELLIPSE An ellipse is a set of points in a plane, such that the sum of the distances of each from two fixed point is a constant. The fixed points are called the foci and the line through them is the axis. Where: F1, F2 = focus v1, v2 = vertex, midpoint of the segment d1 + d2 = 2a d c e = eccentricity = 3 = < 1 d4 a a d= e a2 = b 2 + c 2 2b 2 LR = Latus Rectum = a (x − h)2 (y − k)2 Standard equation: 2 + =1 if the major axis, M.A. is parallel to the x-axis a b2 (y − k)2 (x − h)2 2 + =1 if the major axis, M.A. is parallel to the y-axis a b2 General equation of an ellipse: Ax 2 + By 2 + Dx + Ey + F = 0 where A and B is greater than 0 NOTE: M < 0 no graph (imaginary ellipse) M = 0 graph is a single point M > 0 graph is an ellipse D2 E2 M = −F + + 4A 4B HYPERBOLA A hyperbola is a set of points in a plane, such that the difference of the distances of each from two fixed point is a constant. The fixed points are called the foci and the line through them is the axis. Where: F1, F2 = focus v1, v2 = vertex, midpoint of the segment d1 + d2 = 2a d c e = eccentricity = 3 = >1 d4 a a d= e c 2 =a2 +b 2 2b 2 LR = Latus Rectum = a Equation of Asymptote Asymptote of a curve is a line when the perpendicular distance from a line to a curve approaches zero as the curve extends indefinitely far from the origin. y − k = ±m(x − h) Where (h, k) is the center of the hyperbola and m is the slope, m=b/a if the axis is horizontal and m=a/b if the axis is vertical. Use (+) for upward asymptote and (-) for downward asymptote. (x − h)2 (y − k)2 Standard equation: − =1 if the transverse axis is parallel to the x-axis (Opens left and right) a2 b2 (y − k)2 (x − h)2 2 − =1 if the transverse axis is parallel to the y-axis (Opens up and down) a b2 Length of transverse axis (TA) = 2a Length of conjugate axis (CA) = 2b Length of the focal axis (FA) = 2c General equation of hyperbola: Ax 2 + By 2 + Dx + Ey + F = 0 where A or B is less than 0 DAY 7 Copyright 2010 www.e-reviewonline.com
  • 3.
    Topic: CONIC SECTION,POLAR COORDINATES AND SPACE GEOMETRY POLAR COORDINATES The coordinates of a point in a plane are its distance from a Relationship between Rectangular and Polar fixed point and its direction from a fixed line. Coordinates Where: r = radius vector or modulus θ = amplitude or argument or vectorial angle x = r cos θ r = x2 + y2 y y = r sin θ θ = tan −1 x Curve Tracing on Polar Coordinates 1. The graph of r=k, where k is a constant and greater 4. The graph of r 2 = a2 sin 2θ or r 2 = a2 cos 2θ is a than 0 (k>0) is a circle with center at the pole. lemniscate. Illustration: Illustration: r=2 r 2 = 4 sin 2θ 2. The graph of r = 2a sin θ , c(a,90o) and r=|a| or r = 2a cos θ , c(a, 0o) and r=|a| is a circle that passes through the pole. Illustration: r 2 = 3 cos 2θ r = 4 sin θ r = 4 cos θ 5. The graph of r = a sin(nθ) or r = a cos(nθ) is an n- leaved rose If n is an odd integer, then it is a n-leaved rose If n is an even integer, it is a 2n-leaved rose If n = 1, then there is one petal and it is circular Illustration: 3. The graph of r = a(1 ± sin θ) or r = a(1 ± cos θ) is a r = 3 sin 4θ cardiod. Illustration: r = 3(1 − cos θ) r = 2 cos 2θ r = 1 − cos θ DAY 7 Copyright 2010 www.e-reviewonline.com
  • 4.
    Topic: CONIC SECTION,POLAR COORDINATES AND SPACE GEOMETRY 6. The graph of r = a ± b sin θ or r = a ± b cos θ is a limacon. If |a| < |b| the graph is a limacon with inner loop If |a| = |b| the graph is a cardiod If |a| > |b| the graph is a limacon without a loop Illustration: r = 1 − 2 cos θ r = 4 + sin θ SPACE GEOMETRY Three Dimensional Coordinate System Distance formula in three space Distance between a point (x, y, z) and a plane Ax 1 + By 1 + Cz 1 + D d= A 2 + B2 + C2 Midpoint formula x + x2 x = 1 2 y1 + y 2 y = 2 z1 + z 2 z= 2 Cartesian coordinates (x, y z) d = (x 2 − x 1 )2 + (y 2 − y 1 )2 + (z 2 − z1 )2 Plane The graph of Ax + By + Cz = D is a plane Illustration: Cylinders Any equation in two variables, represents a Graph: 2x + y + 3z = 6 cylindrical surface, that is perpendicular to the two variables and whose generating curve is the plane curve whose equation is given. Illustration: Graph: x2+z2=4 Sphere: Standard equation: (x − h)2 + (y − k)2 + (z − l)2 = r 2 General equation: x 2 + y 2 + z 2 + Dx + Ey + Fz + G = 0 Illustration: Graph: x 2 + y 2 + z 2 − 2x + 4y + 6z − 2 = 0 Graph: y2=4x C(1,-2,3) and r = 4 DAY 7 Copyright 2010 www.e-reviewonline.com
  • 5.
    Topic: CONIC SECTION,POLAR COORDINATES AND SPACE GEOMETRY Quadratic Surfaces 1. Ellipsoid 3. Hyperboloid of Two Sheets x2 y2 z2 2 + 2 + =1 a b c2 2. Hyperboloid of One Sheet x2 y2 z2 2 − 2 − =1 a b c2 4. Elliptic Paraboloid x2 y2 z2 2 + 2 − =1 a b c2 x2 y2 2 − =z a b2 DAY 7 Copyright 2010 www.e-reviewonline.com