Question

Write the standard form equation of a circle with a center at (-5, 5) and a radius of sqrt of 7.

For an equation like this, doesn't the radius equal 7?

So the equation looks like the following -

(x+5)^2 + (y-5)^2 = 7

Answer 1

the equation for a circle is
\[ (x-h)^2 + (y-k)^2 = r^2 \]
where (h,k) is the center, and r is the radius

your equation
(x+5)^2 + (y-5)^2 = 7
is correct

But ***doesn't the radius equal 7?**
no, they tell you the radius is \( \sqrt{7}\). However, \( r^2= 7\)

Answer 2

But I simplify it to 7, right?

Answer 3

*** But I simplify it to 7, right?***
if you mean
\[ r^2= \sqrt{7}\cdot \sqrt{7}= 7 \]
then yes.

but the radius is \( \sqrt7\) (about 2.646 )