Question

Help pleaseee @jim_thompson5910 @Mertsj

Answer 1

you have formula for a circle is x^2 +y^2 = r^2 in which r is radius,
your circle is x^2 +y^2 = 169
see the link?

Answer 2

no

Answer 3

The equation of a circle is:
\[(x-h)^2+(y-k)^2=r^2\]

Answer 4

(h,k) is the center.

What is the center of your circle?

Answer 5

0?

Answer 6

The center has to have an x and a y coordinate.

Answer 7

how do i find the center

Answer 8

Look at the picture.

Answer 9

ok im looking

Answer 10

Where do those two lines cross?

Answer 11

what lines?

Answer 12

im confused

Answer 13

The two lines with arrows on the ends

Answer 14

The only two lines in your picture.

Answer 15

0,0?

Answer 16

I think sometimes they are called coordinate axes.

Answer 17

Yes. They cross at (0,0) and that is the center. So the equation of your circle now becomes:

Answer 18

\[(x-0)^2+(y-0)^2+=r^2\]

Answer 19

Which is the same as:
\[x^2+y^2=r^2\]

Answer 20

And, of course, r is the radius so r^2 is the radius squared.

Answer 21

Are you with me so far?

Answer 22

yes

Answer 23

So compare that equation with the equation given in your problem: