How do you graph x2+y2+6x−8y+9=0?
1 Answer
Feb 12, 2016
circle: centre(-3 , 4) and radius = 4
Explanation:
the general equation of a circle is
x2+y2+2gx+2fy+c=0 the equation here :
x2+y2+6x−8y+9=0
compares with the general equation and is therefore a circle.by comparison of the 2 equations :
obtain: 2g = 6 → g = 3 , 2f = -8 → f = -4 and c = 9
centre = (-g , -f ) = (-3 , 4 )
and radius =
√g2+f2−c=√(−3)2+42−9=√16=4