What is the center and radius of the following circle: (x – 5)2 + (y + 2)2 = 16

A. C (5, -2), r =16
B. C (5, 2), r = 4
C. C (5, -2), r = 4
D. C ( -2, 5), r = 4
would it be d??

Question

What is the center and radius of the following circle: (x – 5)2 + (y + 2)2 = 16

	A.	C (5, -2), r =16
	B.	C (5, 2), r = 4
	C.	C (5, -2), r = 4
	D.	C ( -2, 5), r = 4
would it be d??

jdoe0001 · Answer

http://www.mathwarehouse.com/geometry/circle/images/equation-of-circle/general-formula-equation-of-circle.png so, which one do you think?

anonymous · Answer

i think it is D

jdoe0001 · Answer

nein

marissalovescats · Answer

The center is the opposite of h and then k. and your radius is the # on the otherside of the equation sqrooted.

marissalovescats · Answer

In other words,

Center is-h,k and radius is sqrt of r

anonymous · Answer

oh thank you so much makes lots of sense

marissalovescats · Answer

If I had a circle of 

(x-8)+(y-10)=81 

My center would be opposite h, k so 8,-10. 

And my radius would be sqroot r so sqroot 81 is 9.

anonymous · Answer

if you had that how would you find the diameter

marissalovescats · Answer

Times the sqroot r by 2. So 9*2 would be 18.

But I've never seen that asked about a circle problem like this.

But you figure hmm if r square rooted is the radius and a diameter is 2x a radius... Then after i sqroot my r i times it by 2.

anonymous · Answer

you've been a life saver 
I understand so well now