Question

What is the center and radius of (x - 6)2 + (y + 1)2 = 81

Answer 1

\[\huge Welcome~To~Open~Study\]
@2413

Answer 2

the radius is whatever the equation equals, just squared so:
\[\sqrt{81}=?\]

And yes, welcome

Answer 3

how do you make that big text? >.<

Answer 4

@Luigi0210 select the text (or fancy math expression), then right click and select Show Math As >TeX commands...

Answer 5

@2413 the formula for a circle with radius \(r\) and center \((h,k)\) is \[(x-h)^2+(y-k)^2=r^2\]Does that look similar to anything you have?

Answer 6

I'm using iPad

Answer 7

very painful doing OpenStudy on an iPad, I know!

Answer 8

The center is the vertex : (h,k) \[\large (x-h)^2 + (y-k)^2 = r^2\]your equation \[\large (x -\color{red}{6})^2+(y-\color{red}{(-1)})^2 = 81\]

Answer 9

and the radius is there at the end as r^2

Answer 10

and you can think of that \(r^2\) as \((\sqrt{81})^2\) so \(r = \sqrt{81}\)

Answer 11

I actually feel like Luigi right now >.<

Answer 12

what do you feel like when you aren't feeling like Luigi?

Answer 13

A normal person that isn't being ignored

Answer 14

Looks like we're all being ignored

Answer 15

I summon the powers of negative zone! time to dance :D