Equation of a curve

[Guest]

A curve is traced by a point P(x,y) which moves such that its distance from the point A(-1,1) is three times its distance from the point B(2,-1). Determine the equation of the curve..I understand how to do the graph but i dont know how to figure the equation of a curve

 

[stapel]

Plug (x, y), (-1, 1), and (2, -1) into the Distance Formula. Set the distance between (x, y) and A equal to three times the distance between (x, y) and B. Square both sides. Simplify.

Eliz.