SOLUTION: i need to find the center, and radius of this circle x^2+(y-8)^2 = 81 please help

Algebra ->  Circles -> SOLUTION: i need to find the center, and radius of this circle x^2+(y-8)^2 = 81 please help      Log On


   

Question 123313: i need to find the center, and radius of this circle
x^2+(y-8)^2 = 81
please help
Answer by chitra(359) About Me  (Show Source):
You can put this solution on YOUR website!
The given expression can be written as:

x%5E2+%2B+%28y+-+8%29%5E2+=+81

This can be written as:

%28x+-+0%29%5E2+%2B+%28y+-+8%29%5E2+=+81

Comparing this with the standard equation: %28x+-+h%29%5E2+%2B+%28y+-+k%29%5E2+=+r%5E2

Here the centre is (h, k) and "r" is the radius.

So we get: Center = (h,k) = (0, 8) and r^2 = 81

Therfore radius, r = 9 units

Hence, the solution.