Write an equation for a circle with center at (-2,7) and diameter of 14.

Question

anonymous · Answer

Equation of a circle
$$\Large (x-h)^2+(y-k)^2=r^2$$

(h,k) center
r radius 

Simply plug in

anonymous · Answer

I still don't understand how to

anonymous · Answer

it doesn't really make since

anonymous · Answer

Well a circle's equation is that up there^, ok |dw:1374114635389:dw|

anonymous · Answer

OK see the center right there? Its the point (1,3) and we know our radius is 3 becasue we made it that way

From the equation we just plug it in 

$$(x-(1))^2+(y-3)^2=(3)^2=~~~~~(x-1)^2+(y-3)^2=9$$

anonymous · Answer

And as you know Diameter= 2 times the radius so the radius is half of 14

anonymous · Answer

ah ok thanks

anonymous · Answer

Remember if the center is (-1,-4)
then its $$\Large (x-(-4))^2=(x+4)^2$$

anonymous · Answer

I just meant if one of the coordinates are negative