# Math Help - equation question

1. ## equation question

if i have the problem
(x-1)2+(y-8)2=16
can i just get make that into
(x-1)+(y-8)=4?

2. Originally Posted by brandilee
if i have the problem
(x-1)2+(y-8)2=16
can i just get make that into
(x-1)+(y-8)=4?
no, you cannot do that

what do you want to do?

3. If it is the equation of a circle then yes you may:

Where (x-a)^2 + (y-b)^ 2 = r^2.......

so take the sq root of 16, and you get 4, the radius.

Hope this is clear....

4. i have to graph it, and describe the shape and any other possible information like length, width and center points. im not sure how to put it into a calculator either

5. ## Equation of a circle

It's a circle with radius 4 (the Sq root of 16) and has points (1,8).

6. Originally Posted by brandilee
i have to graph it, and describe the shape and any other possible information like length, width and center points. im not sure how to put it into a calculator either
you don't have to change anything

$(x - 1)^2 + (y - 8)^2 = 16 = 4^2$

this is a circle with radius 4 centered at the point (1,8)

7. so then for this problem
(x+2)2+(y-4)2=36
would be a circle with a radius of 6 and center poitn at (2,4)?

8. Originally Posted by brandilee
so then for this problem
(x+2)2+(y-4)2=36
would be a circle with a radius of 6 and center poitn at (2,4)?
no, for the center, you change the signs. so the center here is (-2,4)

The formula $(x - h)^2 + (y - k)^2 = r^2$ represents a circle with center $(h,k)$ and radius $r$