+594 The standard form of the equation of a circle is (x−4)2+(y−2)2=9.
What is the general form of the equation?
x2+y2+8x+4y+11=0
x2+y2−8x−4y−29=0
x2+y2+8x+4y−29=0
x2+y2−8x−4y+11=0
+9466 (x - 4)2 + (y - 2)2 = 9
We want to multiply this out.
(x - 4)(x - 4) + (y - 2)(y - 2) = 9
(x2 - 8x + 16) + (y2 - 4y + 4) = 9
x2 - 8x + 16 + y2 - 4y + 4 = 9
Rearrange and subtract 9 from both sides.
x2 + y2 - 8x - 4y + 16 + 4 - 9 = 0
x2 + y2 - 8x - 4y + 11 = 0
