The circumference of a circle is 8pi, The center of the circle is shifted three units to the right and one unit down. The equation of this circle is (?)

Answer 1

The formula for circumference is C=2πr

The circumference is 8π, so 8π=2πr.

Divide both sides by 2π:

4=r

Now the equation for a circle is given as

(x-h)²+(y-k)²=r²

where h is the horizontal offset (to the right) and k is the vertical offset (up).

(x-3)²+(y+1)²=16

If you need it in general form:

x²-6x+y²+2y-6=0