Chapter F - Foundations: A Prelude to Functions - Section F.4 Circles - F.4 Assess Your Understanding - Page 38: 27

(a). $(h,k)=(-2,2), r=3$. (b). See graph. (c). $(-2\pm\sqrt 5,0)$, $(0, 2\pm\sqrt 5)$.

(a). $x^2+y^2+4x-4y=1 \longrightarrow (x+2)^2+(y-2)^2=9$, thus $(h,k)=(-2,2), r=3$. (b). See graph. (c). For x-intercept(s), let $y=0$, we get $(-2\pm\sqrt 5,0)$. For y-intercept(s), let $x=0$, we get $(0, 2\pm\sqrt 5)$.