Question

The circle below is centered at (-1, 1) and has a radius of 3. What is itsequation?55A. (x + 1)² + (y− 1)² = 9B. (x-1)² + (y- 1)² = 9C. (x-1)2 + (y+ 1)² = 3O D. (x + 1)² + (y + 1)² = 9-5

Answer 1

Answer: $(x\text{ + 1\rparen}^2\text{ + \lparen y - 1\rparen}^2\text{ = 9 \lparen option A\rparen}$

Explanation:

Given:

The center of the circle = (-1, 1)

radius = 3

To find:

the equation of the circle

center of circle = (h, k)

h = -1, k = 1

r = 3

The standard equation for circle:

$(x\text{ - h\rparen}^2\text{ + \lparen y - k\rparen}^2\text{ = r}^2$$\begin{gathered} (x\text{ - \lparen-1\rparen\rparen}^2\text{ + \lparen y - 1\rparen}^2\text{ = 3}^2 \\ \\ (x\text{ + 1\rparen}^2\text{ + \lparen y - 1\rparen}^2\text{ = 9 \lparen option A\rparen} \end{gathered}$