What is the equation of a circle with its center at (10,−4) and a radius of 2?

Question

a. (x+10)2+(y−4)2=4
b. (x−10)2+(y+4)2=2
c. (x+10)2+(y−4)2=2
d. (x−10)2+(y+4)2=4

Answer 1

if the centre is (a,b) and the radius is r, then the equation is
(x-a)^2 + (y-b)^2 = r^2

Memorize this.

Which of the given choices matches this pattern?

Answer 2

Was the answer D