Question

someone please help me to solve this :( i want to learn!and i suck at geometry!
Circle R has equation (x+2)^2+y^2=4. What is the center and radius of this circle?

Answer 1

The center is (-2, 0)
The radius is 2, I believe

Answer 2

could you explain to me how you did that?

Answer 3

So the basic equation of a circle is: (x-h)^2 + (y-k) =r^2
(h,k) is the center of the circle and r is the radius
since is (x+2)^2, h must equal -2. You can figure this out by take the square root of this which makes it x+2=0 and just solve for x, which is h.
You can do the same thing as for k, since there nothing there then it must be 0.
Since it is 4 at the end with out it being squared then you must square root it.
Does that make any sense

Answer 4

kind of

Answer 5

oh ok i understand how you got the center

Answer 6

Okay, that's good

Answer 7

but what would y equal?

Answer 8

x and y are the places where you can plug in an order pair and see if that pair lies on the circle

Answer 9

Ok thank you (: