How do you find the center and radius of the circle x^2 + y^2 – 2x -3 = 0?

1 Answer
Sep 7, 2016

Center: (1,0)
Radius: 2

Explanation:

Given
color(white)("XXX")x^2+y^2-2x-3=0

Converting into standard circle form:
color(white)("XXX")(x^2-2x)+(y^2)=3

color(white)("XXX")(x^2-2x+1)+(y^2-0)=3+1

color(white)("XXX")(x-1)^2+(y-0)^2=2^2

Which is the standard circle form with
color(white)("XXX")center (1,0), and
color(white)("XXX")radius 2

Here's the graph of the original equation for verification:
enter image source here