Exercise 2 Page 800

(x- h)^2+(y- k)^2= r^2 In this form, ( h, k) is the center of the circle and r is its radius. We are told that the center of the circle is ( 1, -1) and its radius is sqrt(5). This is enough information to write the equation. (x- 1)^2+(y-( -1))^2=( sqrt(5))^2 ⇕ (x-1)^2+(y+1)^2=5