PRE-CALCULUS
Ma’am Grace
Specific objectives:
• illustrate the different types of conic sections: parabola, ellipse,
circle, hyperbola, and degenerate cases
• define a circle
• determine the standard form of equation of a circle
• graph a circle in a rectangular coordinate system
CONIC SECTIONS
A conic section, or simply conic, is a curve formed by the
intersection of a plane and a double right circular cone.
CONIC SECTIONS
A conic section, or simply conic, is a curve formed by the
intersection of a plane and a double right circular cone.
Circle
1
TYPES OF CONIC SECTIONS
Ellipse
2
Parabola
3
Hyperbola
4
TYPES OF CONIC SECTIONS
• Circle - the cutting plane is not parallel to any generator but is perpendicular to the axis
TYPES OF CONIC SECTIONS
• Ellipse - the cutting plane is not parallel to any generator
TYPES OF CONIC SECTIONS
• Parabola - the cutting plane is parallel to one and only one generator
TYPES OF CONIC SECTIONS
• Hyperbola- the cutting plane is parallel to the axis of the double cone
- is perpendicular to the bases of the two cones
TYPES OF CONIC SECTIONS
• Circle
• Ellipse
• Parabola
• Hyperbola
TYPES OF CONIC SECTIONS
• Circle
• Ellipse
• Parabola
• Hyperbola
Point
1
Line
2
Intersecting lines
3
DEGENERATE CASES:
DEGENERATE CASES:
• Point - the cutting plane passes through the vertex of the cone
DEGENERATE CASES:
• Line - the cutting plane passes through the generators
DEGENERATE CASES:
• Intersecting lines - the cutting plane passes through the axis
DEGENERATE CASES:
• Point
• Line
• Intersecting lines
DEGENERATE CASES:
• Point
• Line
• Intersecting lines
KEY ELEMENTS:
• focus (F) - the fixed point of the conic
• directrix (d) - the fixed line d corresponding to the focus
• principal axis (a) - the line that passes through the focus and
perpendicular to the directrix
• vertec (V) - the point of intersection of the conic and its principal
• eccentricity (e) - the constant ratio
KEY ELEMENTS:
CIRCLE
A circle is a set of all coplanar points such that the distance
from a fixed point is constant. The fixed point is called the center of
the cicle and the constant distance form the center is called the
radius of the circle.
EQUATION OF A CIRCLE
Given that (h, k) is the center of the circle;
and (x, y) is a point in the circle
(x - h) 2 + (y - k)2
r
(x - h) 2 + (y - k)2
r
r2 = (x - h) 2 + (y - k)2
(x - h) 2 + (y - k)2 = r2
Standard form
EQUATION OF A CIRCLE
(x - h) 2 + (y - k)2 = r2
General form
x 2 + y 2 + Ax + By + C = 0
Standard form
EQUATION OF A CIRCLE
To derive the equation of a circle whose center C is at the point (0, 0)
and with radius r, let P(x, y) be one of the points on the circle.
(x - 0) 2 + (y - 0)2
r
(x - 0) 2 + (y - 0)2
r
r2 = (x)2 + (y)2
r2 = x2 + y2
EXAMPLES:
Determine the standard form of equation of the circle given its
center and radius.
a. center (0, 0) , radius = 4
b. center (2, 5) , radius = 6
c. center (-2, 7) , radius = 4
d. center (-8, -5) , radius = 3
EXAMPLE a.:
center (0, 0) , radius = 4
(x - h) 2 + (y - k)2 = r2
EXAMPLE A:
center (2, 5) , radius = 6
(x - h) 2 + (y - k)2 = r2
EXAMPLE B:
center (2, 5) , radius = 6
(x - h) 2 + (y - k)2 = r2 x 2 + y 2 + Ax + By + C = 0
EXAMPLE C:
center (-2, 7) , radius = 4
(x - h) 2 + (y - k)2 = r2
EXAMPLE D:
center (-8, -5) , radius = 3
(x - h) 2 + (y - k)2 = r2
QUIZ:
Write the equation of the circle in general form and in standard
form.
1. center (3, -2) , radius = 4
2. center (6, 5) , radius = 8
3. center (0, 8), radius = 11
(x - h) 2 + (y - k)2 = r2
x 2 + y 2 + Ax + By + C = 0
THANK YOU
May GOD bless you always!

PRE-CALCULUS (Lesson 1-Conic Sections and Circles).pptx

  • 1.
  • 2.
    Specific objectives: • illustratethe different types of conic sections: parabola, ellipse, circle, hyperbola, and degenerate cases • define a circle • determine the standard form of equation of a circle • graph a circle in a rectangular coordinate system
  • 3.
    CONIC SECTIONS A conicsection, or simply conic, is a curve formed by the intersection of a plane and a double right circular cone.
  • 4.
    CONIC SECTIONS A conicsection, or simply conic, is a curve formed by the intersection of a plane and a double right circular cone.
  • 5.
    Circle 1 TYPES OF CONICSECTIONS Ellipse 2 Parabola 3 Hyperbola 4
  • 6.
    TYPES OF CONICSECTIONS • Circle - the cutting plane is not parallel to any generator but is perpendicular to the axis
  • 7.
    TYPES OF CONICSECTIONS • Ellipse - the cutting plane is not parallel to any generator
  • 8.
    TYPES OF CONICSECTIONS • Parabola - the cutting plane is parallel to one and only one generator
  • 9.
    TYPES OF CONICSECTIONS • Hyperbola- the cutting plane is parallel to the axis of the double cone - is perpendicular to the bases of the two cones
  • 10.
    TYPES OF CONICSECTIONS • Circle • Ellipse • Parabola • Hyperbola
  • 11.
    TYPES OF CONICSECTIONS • Circle • Ellipse • Parabola • Hyperbola
  • 12.
  • 13.
    DEGENERATE CASES: • Point- the cutting plane passes through the vertex of the cone
  • 14.
    DEGENERATE CASES: • Line- the cutting plane passes through the generators
  • 15.
    DEGENERATE CASES: • Intersectinglines - the cutting plane passes through the axis
  • 16.
    DEGENERATE CASES: • Point •Line • Intersecting lines
  • 17.
    DEGENERATE CASES: • Point •Line • Intersecting lines
  • 18.
    KEY ELEMENTS: • focus(F) - the fixed point of the conic • directrix (d) - the fixed line d corresponding to the focus • principal axis (a) - the line that passes through the focus and perpendicular to the directrix • vertec (V) - the point of intersection of the conic and its principal • eccentricity (e) - the constant ratio
  • 19.
  • 20.
    CIRCLE A circle isa set of all coplanar points such that the distance from a fixed point is constant. The fixed point is called the center of the cicle and the constant distance form the center is called the radius of the circle.
  • 21.
    EQUATION OF ACIRCLE Given that (h, k) is the center of the circle; and (x, y) is a point in the circle (x - h) 2 + (y - k)2 r (x - h) 2 + (y - k)2 r r2 = (x - h) 2 + (y - k)2 (x - h) 2 + (y - k)2 = r2 Standard form
  • 22.
    EQUATION OF ACIRCLE (x - h) 2 + (y - k)2 = r2 General form x 2 + y 2 + Ax + By + C = 0 Standard form
  • 23.
    EQUATION OF ACIRCLE To derive the equation of a circle whose center C is at the point (0, 0) and with radius r, let P(x, y) be one of the points on the circle. (x - 0) 2 + (y - 0)2 r (x - 0) 2 + (y - 0)2 r r2 = (x)2 + (y)2 r2 = x2 + y2
  • 24.
    EXAMPLES: Determine the standardform of equation of the circle given its center and radius. a. center (0, 0) , radius = 4 b. center (2, 5) , radius = 6 c. center (-2, 7) , radius = 4 d. center (-8, -5) , radius = 3
  • 25.
    EXAMPLE a.: center (0,0) , radius = 4 (x - h) 2 + (y - k)2 = r2
  • 26.
    EXAMPLE A: center (2,5) , radius = 6 (x - h) 2 + (y - k)2 = r2
  • 27.
    EXAMPLE B: center (2,5) , radius = 6 (x - h) 2 + (y - k)2 = r2 x 2 + y 2 + Ax + By + C = 0
  • 28.
    EXAMPLE C: center (-2,7) , radius = 4 (x - h) 2 + (y - k)2 = r2
  • 29.
    EXAMPLE D: center (-8,-5) , radius = 3 (x - h) 2 + (y - k)2 = r2
  • 30.
    QUIZ: Write the equationof the circle in general form and in standard form. 1. center (3, -2) , radius = 4 2. center (6, 5) , radius = 8 3. center (0, 8), radius = 11 (x - h) 2 + (y - k)2 = r2 x 2 + y 2 + Ax + By + C = 0
  • 31.
    THANK YOU May GODbless you always!