Question

What is the equation of the circle with center (1,1) that passes through the point (-3,4)?

Answer 1

(x - 1)2 + (y - 1)² = 5²

Explanation:

Adapt the standard equation of a circle with center at (h, k) and radius r:

(x - 1)^2 + (y - 1)^2 = r^2

Here one point on the circle is (-3, 4), and so the radius is √[(-3)² + 4² ] = 5

Thus, the desired equation is:

(x - 1)^2 + (y - 1)^2 = 5^2 or (x - 1)2 + (y - 1)² = 5²