Question

What is the equation of a circle with center (-7,-3) and radius 2?

a. (x+7)^2 + (y+3)^2=4
b. (x-7)^2 + (y-3)^2=4 <----my answer
c. (x-7)^2 + (y-3)^2=2
d. (x+7)^2 +(y+3)^3=2

Answer 1

well the general form of the equation is

\[(x - h)^2 + (y - k)^2 = r^2\]

the centre is at (h, k) and the radius is r

so substitute h = -7 and k = - 3 and r = 2

oh, and your answer is incorrect

Answer 2

would it be positive instead?

Answer 3

@campbell_st

Answer 4

ya it would be positive

Answer 5

well if you substitute h = -7 into (x - h)

you get (x + 7)

Answer 6

ok

Answer 7

would it be a

Answer 8

it would be A