## Sunshine447 3 years ago A circle is shown on the coordinate plane below. http://learn.flvs.net/webdav/assessment_images/educator_geometry_v14/pool_Geom_3641_0802_07/image0034e849df3.gif What is the equation of this circle? x2 + (y + 1)2 = 4 x2 + (y – 1)2 = 2 x2 + (y + 1)2 = 2 x2 + (y – 1)2 = 4

1. Sunshine447

@ParthKohli @Hero

2. Sunshine447

@ganeshie8

3. Sunshine447

I think it's the first one

4. Sunshine447

is it the first choice? I'm just double checking

5. ganeshie8

check again :)

6. Sunshine447

why is it the last one?

7. Sunshine447

wouldnt it be 2^2=4 so its the first one? Dont you have to add not subtract?

8. ganeshie8

general form of equation is : (x-h)^2 + (y-k)^2 = r^2 can you tell whats the center (h, k) and radus r, from the figure ?

9. ganeshie8

yeah radius you got it correct !!

10. Sunshine447

yes, the center is 0,1 and the radius is 2

11. Sunshine447

wait.... so which one is it?

12. Sunshine447

1st or last?

13. ganeshie8

center = (h, k) = (0, 1) (x-h)^2 + (y-k)^2 = r^2

14. ganeshie8

plug in h and k values

15. ganeshie8

(x-0)^2 + (y-1)^2 = 2^2 x^2 + (y-1)^2 = 4

16. Sunshine447

so the first one?

17. ganeshie8

does that help/make sense ?