Graphing a Circle: Find Center, Radius & Intercepts

[elitespart]

Consider x^2 + y^2 – x + 2y + 1 = 0.
(a) Find the coordinates of the center and the length of the radius.
(b) Determine the coordinates of the intercepts.
(c) Graph the circle.



I'm really lost on this one. I tried plugging in numbers but I seriously doubt that's how I'm supposed to do it. Can someone point me in the right direction? Thanks

 

[symbolipoint]

Standard Form versus General Form.
Completing the Square.

 

[elitespart]

oh so just (x-1/2)^2 + (y+1)^2 = 1/4? center would be at (1/2, -1) and radius is sqrt(1/4)=(1/2)?

 

[tiny-tim]

oh so just (x-1/2)^2 + (y+1)^2 = 1/4? center would be at (1/2, -1) and radius is sqrt(1/4)=(1/2)?

Yup!