# How do you write the general form given a circle that passes through the given #(x-2)^2 + (y+1)^2 = 9#?

##### 1 Answer

Apr 1, 2016

#### Explanation:

The general form of the equation of a circle is.

#x^2 + y^2 + 2gx + 2fy + c = 0 # To write the given equation in this form , requires expanding the brackets and rearranging into the general form.

#(x-2)^2 = x^2-4x+4" and " (y+1)^2 = y^2+2y+1 # hence:

#x^2-4x+4+y^2+2y+1 = 9 #

#rArr x^2+y^2+4x+2y-4 = 0 " is in general form "#