Question

Write the equation of a circle whose center is at (-11,15) and whose radius is 9

Your answer must be in Standard Form AND simplified

Answer 1

(x + 11)² + (y - 15)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 is the radius

here (h, k ) = (- 11, 15 ) and r = 9 , then

(x - (- 11) )² + (y - 15)² = 9² , that is

(x + 11)² + (y - 15)² = 81