x2 + y2 = 1

x2 + y2 = 25

x2 + y2 = 64

The general equation of a circle is:

→ the centre of each of these circles is ( , )→ the x-intercepts are at x =

x = x =

→ in general, x-intercepts are at x =

Ex 1: Determine the equation of each circle centered at (0, 0) that passes through the given point.

a) (-4, 3) b) (8, -6) c) (5, 11)

Ex 2: Determine the other endpoint of the diameter through each circle from example 1.

a) b) c)

Ex 3: Determine the x-intercepts and y-intercepts of each circle from example 1.

a) b) c)

x

y

Assignment: 2.3 p.91 #1, 2a, 3a, 4, 6, 11, 12, 14

Equation of a Circle