What is the standard form of the equation of a circle with center of a circle is at (-15,32) and passes through the point (-18,21)?

1 Answer
Nov 14, 2015

Answer:

#(x+15)^2+(y-32)^2=130#

Explanation:

The standard form of a circle centred at (a,b) and having radius r is #(x-a)^2+(y-b)^2=r^2#.

So in this case we have the centre, but we need to find the radius and can do so by finding the distance from the centre to the point given :

#d((-15,32);(-18,21))=sqrt((-18-(-15))^2+(21-32)^2)=sqrt130#

Therefore the equation of the circle is

#(x+15)^2+(y-32)^2=130#