Question

The equation of a circle is shown below.

(x -5)2 + (y + 2)2 = 64

The radius of the circle is ________ units.

Answer 1

@Gin_Ichimaru
@micahwood50
@Loujoelou
@surjithayer
@maywadee313
@Zale101
@zepdrix

Answer 2

\[(x -5)^2 + (y + 2)^2 = r^2\]
\[r^2=64, \qquad r=?\]

Answer 3

if r^2=64
then r equals what?

Answer 4

I actually don't know. :(

Answer 5

So we have r^2=64.
To solve for r, take the square root of both sides.
r=sqrt(64).

Use a calculator if you aren't sure about this one! :)

Answer 6

erm, okay.

Answer 7

What do you mean by both sides?

Answer 8

I got 4096. :(

Answer 9

\[\Large r^2=64\]In the land of math, we can manipulate both sides and the equation stays balanced. So we'll take the square root of r^2 and the square root of 64.\[\Large \sqrt{r^2}=\sqrt{64}\]Squareroot and square are inverse operations of one another, they'll undo each other in this instance.\[\Large r=\sqrt{64}\]

Hmm 4096? It sounds like you `squared` your 64.
You want to `square root` your 64.

Answer 10

How?
Did I happen to Multiply 64 by 64?
oops, my mistake. *blushing*

Answer 11

Anyone? :(

Answer 12

Yes you multiplied 64 and 64 :)
You want to instead use your calculators \(\large \sqrt{}\quad\)button.

Answer 13

okay.
8

Answer 14

yay good job \c:/

Answer 15

Aww, thanks.
Imma medal you! :D