Question

Graph the circle with center at (3,-2), which also passes through the point (0,2)

Answer 1

The first thing you have to do is use the distance formula to get the radius. That will be the distance from the center to the other point. Are you able to do that, or do you need help with that?

Answer 2

need help, what is the formula

Answer 3

btw, I was graphing it while you were answering, it looks like:

Answer 4

\[d = \sqrt{(x _{2} - x _{1})^{2} + (y _{2} - y _{1})^{2}}\]

Answer 5

That "d" will be your (r)adius for the equation of a circle with center at (h, k):\[(x - h)^{2} + (y - k)^{2} = r ^{2}\]

Answer 6

so x2 is 0 and x1 is 3

Answer 7

Yes.

Answer 8

Are you able to get the radius?

Answer 9

i got -3?

Answer 10

Are you saying you got -3 for the radius?

Answer 11

I got -3 as the answer to that formula

Answer 12

or 1.414

Answer 13

Well, if you did, you took the square root of something and got -3. It will help you immensely if you show me your work and I can then see where you went wrong.

Answer 14

Actually, looking at those numbers, I can see where you probably went wrong without you even writing it out.

2 - (-2) = 4

You could also go:

-2 - 2 = -4

Either one squared is 16

Answer 15

\[r = d = \sqrt{(3 - 0)^{2} + (-2 - 2)^{2}} = \sqrt{9 + 16} = \sqrt{25} = 5\]

Answer 16

(0-3)^2+(2+2)^2 ....-3^2=9 9+16=25 so 5?

Answer 17

Yes, you can use either point for point #1 so either way works.

Answer 18

So, the equation for the circle is:\[(x - 3)^{2} + (y + 2)^{2} = 25\]

Answer 19

All good now, @adillie ?

Answer 20

Thank you

Answer 21

uw! Good luck to you in all of your studies and thx for the recognition! @adillie

Answer 22

I have one more question... is (3,3) (8,-2) (-2,-2) (3,-7) points on that circle?

Answer 23

I just got back to my computer. Yes, they are all points on that circle. You can determine that from either the equation or the graph. @adillie