Find the equation and length of common chord of the circle
and
First, solve for y in each of the equations. Start by moving all x terms and constants to the right side
complete the square
divide by the coefficient of the quadratic term
taking the root and adding
Do the same with the other equation and solve the system.
Something wrong here. Those two circles don't intersect at all, so how can they have a common chord? (The centres of the circles are at (2,–4) and . The distance between these points is about 6.86. This is a lot more than the sum of the two radii, which are and , both of them less than 2.)
Edit. Oops! First radius is , not . Thanks to skeeter for spotting that.