## Sunshine447 2 years ago I really don't get this lesson question: Which statement is true for the circle? http://learn.flvs.net/webdav/assessment_images/educator_geometry_v14/0800/0800_G8_Q29a.gif Its center is at the ordered pair of 1 over 2, minus 1, and the radius is minus five over two units. Its center is at the ordered pair of minus 1 over 2, 1, and the radius is five over two units. Its center is at the ordered pair of 1 over 2, minus 1, and the radius is five over two units. Its center is at the ordered pair of minus 1 over 2, 1, and the radius is minus five over two units.

1. Sunshine447

@amistre64

2. Sunshine447

@jim_thompson5910

3. mathstudent55

4. Sunshine447

it works on mine

5. Sunshine447

@AccessDenied

This link works for you because it is on a course website and you have to be logged in to view it, do you know how to take a screenshot?

7. Sunshine447

umm i think lemme try

Okay if you need help, reply back with your computer OS(Operating System, Mac or Windows)

9. Sunshine447

Here's the whole thing as pasted from the lesson

10. phi

11. Sunshine447

okay...?

12. phi

that rules out 2 of your choices

13. Sunshine447

so it's either B or C, but I still don't know which

14. phi

the (x,y) pair at the center will make the (x-a)^2 and (y-b)^2 terms zero does that make sense?

15. Sunshine447

not really, no...

16. phi

usually they say (x-h)^2 + (y-k)^2 = r^2 and the center is at (h,k) with radius r

17. Sunshine447

how do we get h and k?

18. phi

so if you see (x- 1/2) that means the x value of the center is +1/2

19. Sunshine447

okay

20. phi

in this case you match your equation to the "generic" one match (x-h)^2 + (y-k)^2 = r^2 (x-1/2)^2 + (y + 1)^2 = 25/4

21. phi

matching y-k to y+1 you have to rewrite y+1 as y - (-1) now you see y - k matches y - (-1) and k is -1

22. phi

or remember that you want the y value that makes (y+1)^2 zero. that would be y= -1

23. Sunshine447

so the Y is -1?

24. Sunshine447

then it's C? Right?

25. phi

yes.

26. Sunshine447

Thank you soooooo much! I'm going to go write you a testimonial! haha

27. phi

thank you