# How do you write the equation in standard form of the circle center at P(2, -5) and a diameter of 8 units?

##### 1 Answer

Jan 25, 2016

# (x - 2 )^2 + (y + 5 )^2 = 64 #

#### Explanation:

The standard form of the equation of a circle is :

# (x - a )^2 + (y - b )^2 = r^2 # where (a , b ) are coordinates of centre and r , the radius.

In this question (a , b ) = (2 , - 5 ) and r = 4 ( since d = 8 )

equation is :

# (x - 2 )^2 + (y + 5) ^2 = 16 #