Answer
(a) center $(h,k)=(1,2)$ and radius $r=3$.
(b) See graph.
(c) $(1\pm\sqrt 5,0)$, $(0,2\pm2\sqrt 2)$.
Work Step by Step
(a) Given $x^2+y^2-2x-4y-4=0\longrightarrow (x-1)^2+(y-2)^2=9$, we can find the center $(h,k)=(1,2)$ and radius $r=3$.
(b) See graph.
(c) We can find the x-intercept(s) (let y=0) $(1\pm\sqrt 5,0)$, y-intercept(s) (let x=0) $(0,2\pm2\sqrt 2)$.
