Question

The equation of a circle is `(x + 10)^2 + (y - 4)^2 = 100`. What is the center and radius of the circle?

Answer 1

Center is `(-10,4)` andradius is `10`.

Explanation:

If the center of circle is `(h,k)` and its radius is `r`, equatiion of circle is

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

Here equation of circle is `(x+10)^2+(y-4)^2=100` can be written as

`(x-(-10))^2+(y-4)^2=10^2`

Hence, center is `(-10,4)` andradius is `10`.

graph{((x+10)^2+(y-4)^2-100)((x+10)^2+(y-4)^2-0.2)=0 [-30.5, 13.5, -7.4, 14.6]}