Transcript 9.6 Circles in the Coordinate Plane

9.6
Circles in the Coordinate Plane
Date: ____________
9.3 Circles
Circles
Standard Equation of a Circle
(x – h)2 + (y – k)2 = r2
center: (h, k)
radius: r
Write the equation of the circle that
whose center is at (5,3) and whose
radius is 6.
( x  h)  ( y  k )  r
2
( x  5)  ( y  3)  6
2
2
2
2
2
( x  5)  ( y  3)  36
2
2
Write the equation of the circle that
whose center is at (-2,4) and
whose radius is 3.
( x  h)  ( y  k )  r
2
2
2
( x   2)  ( y  4)  3
2
2
( x  2)  ( y  4)  9
2
2
2
Write the equation of the circle that
whose center is at (-1,-6) and
whose radius is 6.
( x  h)  ( y  k )  r
2
2
2
( x   1)  ( y   6)  6
2
2
( x  1)  ( y  6)  36
2
2
2
Write the equation of the circle that
whose center is at (0,4) and whose
radius is 2.
( x  h)  ( y  k )  r
2
( x  0)  ( y  4)  2
2
2
2
2
2
x  ( y  4)  4
2
2
Find the center and radius of the
circle. Then write the equation of
the circle.
y
Center = (1,2)
Radius = 3
x
( x  1)  ( y  2)  3
2
2
( x  1)  ( y  2)  9
2
2
2
Find the center and radius of the
circle. Then write the equation of
the circle.
y
Center = (-1,0)
Radius = 4
x
( x   1)  ( y  0)  4
2
2
( x  1)  y  16
2
2
2
Find the center and radius of the
circle. Then graph the circle.
( x  1)  ( y  3)  16
2
Center = (-1,3)
2
y
Radius = 4
x
Find the center and radius of the
circle. Then graph the circle.
( x  3)  ( y  2)  4
2
Center = (-3,-2)
2
y
Radius = 2
x
Find the center and radius of the
circle. Then graph the circle.
( x  4)  ( y  1)  25
2
Center = (4,1)
2
y
Radius = 5
x