Question

Given the center of a circle as ( 1, -1 ) and a point on the circle at (4 , 2). Write the equation of the circle. *

Answer 1

Answer:

(x − 1)² + (y + 1)² = 18

Step-by-step explanation:

Equation of a circle is:

(x − h)² + (y − k)² = r²

where (h, k) is the center and r is the radius.

The center is (1, -1), so plugging that in:

(x − 1)² + (y + 1)² = r²

A point on the circle is (4, 2), so plugging that in:

(4 − 1)² + (2 + 1)² = r²

18 = r²

Therefore, the equation is:

(x − 1)² + (y + 1)² = 18