Question

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

Answer 1

Equation of a circle
\[\Large (x-h)^2+(y-k)^2=r^2\]

(h,k) center
r radius

Simply plug in

Answer 2

I still don't understand how to

Answer 3

it doesn't really make since

Answer 4

Well a circle's equation is that up there^, ok

Answer 5

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

\[(x-(1))^2+(y-3)^2=(3)^2=~~~~~(x-1)^2+(y-3)^2=9\]

Answer 6

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

Answer 7

ah ok thanks

Answer 8

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

Answer 9

I just meant if one of the coordinates are negative