10.3 Circles

A circle is. . .

Standard form for the equation of a circle:

Circle Demo

Example 1. Write the equation of the circle.

a. Center (-4, 3), radius 4

b. Center (5, -2), radius 8

Example 2. Find the center and radius of each circle.

a. (x – 16)2 + (y + 9)2 = 144

b. (x + 8)2 + (y + 3)2 = 121

c. x2 + y2 = 2

Example 3. Find the center and radius.

a. x2 + y2 - 6x – 2y + 4 = 0

b. x2 + y2 – 14x – 2y = -1

Assignment: