Question

Which equation of a circle represents the picture?

A) (x)^2+(y)^2=10
B) (x-5)^2+(y-5)^2=25
C) (x)^2+(y^2)=25
D) (x+5)^2+(y+5)^2=10

Answer 1

C) x² + y² = 25

Explanation:

the center is (0, 0).

so, the generic circle equation

(x−h)² + (y−k)² = r². The center is (h, k) and the radius is r units.

for (h, k) = (0, 0) this gives us the equation above.

and r we can easily see as the distance from the center to one of the points on the circle arc. which is 5, as the coordinates tell us.