SAT Circle Question

Test Preparation
1

Question I came across in my prep:

x^2+y^2+4x-2y=-1 what is the radius?

Is there any way to graph this on the TI-84 graphing calculator? Can’t figure out how to graph an equation with an x and a y. Figured it’d just be one less equation I had to memorize if I could graph

Thanks

2

you have to use a process called completing the square (look it up). once you do that, youll have the equation in the form of (x-h)^2(y-k)^2=r^2, where r is the radius

3

sorry i meant the equation will be in the form of (x – h)^2 + (y – k)^2 = r^2