SOLUTION: Given the equation (x-3)^2 + (y+2)^2 = 9, (a)find the center and radius; (b)graph; (c)find the intercepts, if any. Please help! I am completely confused.

Algebra ->  Circles -> SOLUTION: Given the equation (x-3)^2 + (y+2)^2 = 9, (a)find the center and radius; (b)graph; (c)find the intercepts, if any. Please help! I am completely confused.      Log On


   

Question 534333: Given the equation (x-3)^2 + (y+2)^2 = 9, (a)find the center and radius; (b)graph; (c)find the intercepts, if any. Please help! I am completely confused.
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Compare the given equation
%28x-3%29%5E2%2B%28y%2B2%29%5E2+=+9 with
%28x-h%29%5E2%2B%28y-k%29%5E2+=+r%5E2} This is the general form of the equation of a circle with its center at (h,k) and a radius of r.
So you can easily identify the center and radius of the given equation as:
Center at (3, -2) and radius of 3.
To graph the equation, you must first solve the equation for y:
%28x-3%29%5E2%2B%28y%2B2%29%5E2+=+9 Subtract %28x-3%29%5E2 from both sides.
%28y%2B2%29%5E2+=+9-%28x-3%29%5E2 Take the square root of both sides.
y%2B2+=+sqrt%289-%28x-3%29%5E2%29 Subtract 2 from both sides.
y+=+sqrt%289-%28x-3%29%5E2%29-2 and y+=+-sqrt%289-%28x-3%29%5E2%29-2 Now graph these two equations.