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
