Question

how do you find the center of a circle with the equation x^2+y^2=81

Answer 1

\[\huge\rm (x-h)^2 +(y-k)^2 +r^2\] where (h,k) is the center and r is radius
so there aren't any number with x and y what does that mean ?

Answer 2

That the center is at 0,0 but when I put that in it said it is wrong

Answer 3

hmm weird let's graph

Answer 4

center at (0,0)