Identify the center and radius of each. Then sketch the graph.

Question

(x + 3)² + (y - 1)² = 4

Answer 1

The equation of a circle is:

(x-h)² + (y-k)² = r²

where (h,k) is the location of the center (x=h, y=k) and r is the radius. Can you find the values of h, k, and r in the equation you are given?

To sketch the graph, place the center at point (h,k), then measure a radius from the center out to length r in several places then sketch in a circle. Better yet, use a circle compass.

Answer 2

(x + 3)² + (y - 1)² = 4

The circle equation definition

(x-a) ² + (y - b)² = r²

This is the circle equation with the radius, r, centered at (a, b).

Rewriting (x + 3)² + (y-1)² = 4 in the form of the standard circle equation

(x -(-3))² + (y - 1)² = 2²

Therefore, the circle properties are

(a, b) = (-3, 1), r = 2