Find the center and radius of the circle. x^(2)+y^(2)-4x+6y-3=0
I know I'm supposed to use the h and k stuff, but I can't find it in my notes.

Question

Find the center and radius of the circle. x^(2)+y^(2)-4x+6y-3=0
I know I'm supposed to use the h and k stuff, but I can't find it in my notes.

anonymous · Answer

@phi

anonymous · Answer

@amistre64

mathmale · Answer

How about looking this up in your textbook, or even through an Internet search (for "standard equation of a circle")?

Note that your x^(2)+y^(2)-4x+6y-3 can be rearranged as follows:  x^(2) - 4x +y^(2) +6y - 3 = 0; all I did was to group similar terms.

Review "completing the square" in your textbook or notes or online.  Given x^(2) - 4x, how would you complete the square to obtain x^(2) - 4x + c - c ?

mathmale · Answer

Yes, you will end up with that "h and k stuff."  But that could be a good thing!