Question

Given the equation (x + 3) ^ 2 + y ^ 2 = 81 choose ALL correct answers

1.The center of the circle would lie on the x-axis.

2. The center of the circle would lie on the y-axis.

3.The center of the circle would lie in a quadrant.

4. The radius is 9

5. The radius is 40.5

6.The radius is 81

7. The diameter is 18

8.The diameter is 81

9. The diameter is 162 Help please

Answer 1

The equation of a circle having the center (a, b) and radius r could be formulated by:

(x - a)^2 + (y - b)^2 = r^2

A circle, which has equation form: (x + 3) ^ 2 + y ^ 2 = 81, can be turned into:

(x - -3)^2 + (y - 0)^2 = 9^2

=> center (-3, 0)

=> radius = 9

=> Option 1 is correct

=> Option 4 is correct

=> Option 7 is correct

Hope this helps!

:)