Question

Identify the center and radius of each circle.

Answer 1

Answer:

1. Centre = (1,-3); r = 2;  

2. Centre = (2,-1); r = 4  

Step-by-step explanation:

1. (x - 1)² + (y + 3)² = 4

The centre-radius equation for a circle is

(x - h)² + (y - k)² = r²

The centre of the circle is at (h, k) and the radius is r.

By comparing terms in the two equations we see that

h = 1, k = -3, r = 2

Centre = (1,-3); r = 2

2. (x - 2)² + (y + 1)² = 16

Here,

h = 2, k = -1, r = 4

Centre = (2,-1); r = 4

The figure below shows the first circle in red and the second in green.