Question

A circle is shown on the coordinate plane below.



What is the equation of this circle?
Answer
(x + 1)2 + y2 = 2
(x – 1)2 + y2 = 2
(x + 1)2 + y2 = 4
(x – 1)2 + y2 = 4

Answer 1

what's the center, Danny?

Answer 2

I say it is, 1,0

Answer 3

ok. you looking at the graph right? what's the radius of the circle?

Answer 4

R=2

Answer 5

so R=2 means you can eliminate two of those choices... which one?

Answer 6

which two?

Answer 7

C and D are not it. is it B?

Answer 8

C or D ARE possiblilities because R=2... so R^2 = 4

Answer 9

oh dang it forgot!.

Answer 10

so then A and B are out of the picture?

Answer 11

yeah... remember this:
(x-h)^2 + (y-k)^2 = r^2

Answer 12

since the center is (1, 0) which is it?

Answer 13

D

Answer 14

correct ... :) good job Danny!

Answer 15

cool, thanks for your help again!