##### find the center and radius of each side

 Mathematics Tutor: None Selected Time limit: 1 Day

May 5th, 2015

You wrote correctly

The center is (0,0)

May 5th, 2015

But how? That's what I'm lost on.i don't know how to set it up

May 5th, 2015

I got the answer from someone else.i don't know how to set it up to find the center

May 5th, 2015

The standatd formula for the circle with the centre in point (a,b) is

(x-a)^2+(y-b)^2=r^2

We have (x-0)^2+(y-0)^2=72, so the centre is in the point (0,0)

May 5th, 2015

So unless there is a number before X, it's 0?

May 5th, 2015

If there is no number before x and y, then the center has the coordinates (0,0)

May 5th, 2015

Ohhh okay. So how would I go about the numbers? Do I square them all?

May 5th, 2015

no, for example (x-5)^2+(y-2)^2=25 indicate that the center is (5, 2)

to determine the center you just need to see on the values of a and b: (x-a)^2+(y-b)^2=r^2

May 5th, 2015

So if on the test Friday he gives us a problem that says that, we just write those numbers as pair?

May 5th, 2015

yes if the equation will be in such form

But if the equation will be in the form for example (x+5)^2+(y+2)^2=25, the center will be (-5, -2).

So you just need to look at the sign in the (). If it is +, the point is -, and vice versa.

May 5th, 2015

Okay. I think I may have it now

May 5th, 2015

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May 5th, 2015
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May 5th, 2015
Dec 10th, 2016
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