Question

Write the equation of a circle with center (7, -12) and radius 9.

Answer 1

(x - 7)² + (y + 12)² = 81

Explanation:

The equation of a circle in standard form is

(x - h)² + (y - k)² = r²

where (h, k) are the coordinates of the centre and r the radius

Here (h, k) = (7, - 12) and r = 9, thus

(x - 7)² + (y - (- 12))² = 9², that is

(x - 7)² + (y + 12)²= 81

Answer 2

( x-7)^2 + ( y+12) ^2 = 81

Explanation:

The equation of a circle can be written in the form

( x-h)^2 + ( y-k) ^2 = r^2 where ( h,k) is the center and r is the radius

( x-7)^2 + ( y--12) ^2 = 9^2

( x-7)^2 + ( y+12) ^2 = 81