SOLUTION: What is the equation of a circle with center(1,-3) and tangent to the line x=3?I think the answer is (x-1)+(y+3)=4 BUT I am not confident, can someone please help me :)

Algebra ->  Circles -> SOLUTION: What is the equation of a circle with center(1,-3) and tangent to the line x=3?I think the answer is (x-1)+(y+3)=4 BUT I am not confident, can someone please help me :)      Log On


   

Question 139718: What is the equation of a circle with center(1,-3) and tangent to the line x=3?I think the answer is (x-1)+(y+3)=4 BUT I am not confident, can someone please help me :)
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!
Very close. You have the radius (2) and the center (1,-3) correct, but you forgot one rather important part of the equation of a circle.

A circle with radius r and center at (h,k) is %28x-h%29%5E2%2B%28y-k%29%5E2=r%5E2

So you need to add the exponents to each of the binomials:

Not: %28x-1%29%2B%28y%2B3%29=4, but %28x-1%29%5E2%2B%28y%2B3%29%5E2=4