Question

X^2+2x+y^2=20 find the center and radius of the circle

Answer 1

Center: (-1,0)

Radius:
`√(21)`

Explanation:

You can complete the square for x:

`x^2+2x+y^2=20 \\\\(x^2+2x+1)-1+y^2=20 \\\\(x+1)^2+y^2=21`

The standard form for a circle is
`(x-h)^2+(y-k)^2=r^2`, where h is the x coordinate of the center of the circle, k is the y coordinate, and r is the radius. Therefore, the center of this circle is at (-1,0), and the radius is
`√(21)`. Hope this helps!