Question

Which equation is the equation of a circle with a diameter of 10 cm and a center at (-3,6) ?

A. (x - 3)^2 + (y + 6)^2 = 100

B. (x + 3)^2 + (y - 6)^2 = 100

C. (x - 3)^2 + (y + 6)^2 = 25

D. (x + 3)^2 + (y - 6)^2 = 25

Answer 1

B

You use the equation (x-h)^2+(y-k)^2=r^2 with the center of the circle being (h,k) and the radius being r. When you plug all of this information in, you get the equation (x+3)^2+(y-6)^2=100, which is the same as option B.