Question

a) Find the center-radius form of the equation of the circle with center (-1,2) and radius 4.b) Graph the circle.

Answer 1

a) the equation for a circle is:

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

being, r = radius and the center (h,k)

so we have

h=-1

k=2

r= 4

if we replace on the equation, we get:

`(x+1)^2+(y-2)^2=4^2`

and that's the answer to a)

you can write it like

`(x+1)^2+(y-2)^2=16`

b) now, to graph, you need to, go to the center point (x=-1 and y=2) and make a circle from there with radius 4