Question

What is the equation of the circle below?

Answer 1

I can't quite remember how to do this. Thanks!

Answer 2

Equation of circle with centre at origin and radius r units is given by
x^2+y^2=r^...

can you move on from here...

Answer 3

I know the equation for some reason I can't remember what to plug into it /:

Answer 4

what is center of the circle here...

Answer 5

(0,0)

Answer 6

yup
and the radius is how many units

Answer 7

Wait is it 9^2+92^=9^2??

Answer 8

The radius is 9 units.

Answer 9

so just replace r by 9

Answer 10

Okay so x^2+y^2=9^2

Answer 11

yup
thats gr8...

Answer 12

Okay so is it 9^2+9^2=9^2?

Answer 13

no

Answer 14

in the equation of circle x^2 and y^2 must be there

Answer 15

In my notes it states that r= x^2+y^2 square rooted.

Answer 16

just you can replace 9^2 by 81

Answer 17

thats also correct ..
but you don't need to plug 9 instead of x and y

Answer 18

Okay so the answer would be x^2+y^2=81?

Answer 19

yup...

Answer 20

Got it! Thanks!!!:)

Answer 21

yw