# How do you find the center and radius for #x^2 + y^2 -12y + 25= 0#?

##### 1 Answer

Aug 1, 2016

Centre is thus

#### Explanation:

We want to complete the squares. As there is no x term of degree one we leave it as is and focus on the y.

Subtract 25 from both sides:

Square half the coefficient of

Recognise that because the constant term is half the coefficient we can convert the left hand side to squared form and simplify the right hand side.

This is now in the standard form

Centre is thus