The equation of a circle is (x + 7)2 + (y + 2)2 = 49. Determine the length of the diameter.
(step by step please so i can learn)

Question

The equation of a circle is (x + 7)2 + (y + 2)2 = 49.  Determine the length of the diameter. 
(step by step please so i can learn)

mikurout · Answer

Do you know the equation of circle?

anonymous · Answer

(x-h)^2+(y-k)^2=r^2 @mikurout

mikurout · Answer

Here r stands for which term?

anonymous · Answer

radius?
@mikurout

mikurout · Answer

Yes

bradely · Answer

radius r = 7
diameter,d = 2r
                  =2(7)
                  =14 
Source:www.mathskey.com

mikurout · Answer

Now you know the value of radius.

mikurout · Answer

As r^2 = 49
so r = $$\sqrt{49}$$
=7

anonymous · Answer

so if the formula says "(x-h)' what causes the minus to change to addition? @mikurout

mikurout · Answer

It is the position of center

anonymous · Answer

so for example if the centers coordinates are (6,7) would that be addition or subtraction

anonymous · Answer

@mikurout

mikurout · Answer

substraction

anonymous · Answer

so when the cordinates are positive you subtract and when theyre negative youu add? ok i get it now thanks @mikurout

mikurout · Answer

Yes

mikurout · Answer

It is just the distance formula , that we are using for finding out the distance between center and any point on the circle.