Question

Assistance needed.
Show that the following equation represents a circle
x^2+y^2-4x+2y+1=0.
Find the center and radius of the circle.

Answer 1

\[x ^{2}+y ^{2}-4x+2y+1=0\]
\[(x ^{2}-4x+4)+(y ^{2}+2y+1)+1=4+1\]
\[( x-2)^{2}+(y+1)^{2}=4\]

Answer 2

so its center is (2,-1) and radius is 2 unit

Answer 3

How did you figure that?

Answer 4

i add 4 and 1 in both side...

Answer 5

Oh, I see that now. Thank you.

Answer 6

you are welcome...:)