# Equation of the curve..I'm not sure if this is Pre-Calculus

• Aug 20th 2009, 10:47 AM
mkat5678
Equation of the curve..I'm not sure if this is Pre-Calculus
I can't seem to figure out how to answer this problem! It's nothing i learned last year in pre-calc which is why i dont think it is pre-calc. but its in my math packet for next year's calc class...

A curve is traced by a point P(x,y) which moves such that its distance form the point A(-1,1) is three times its distance from the point B(2,-1). Determine the equation of the curve.
• Aug 20th 2009, 11:12 AM
skeeter
Quote:

Originally Posted by mkat5678
I can't seem to figure out how to answer this problem! It's nothing i learned last year in pre-calc which is why i dont think it is pre-calc. but its in my math packet for next year's calc class...

A curve is traced by a point P(x,y) which moves such that its distance form the point A(-1,1) is three times its distance from the point B(2,-1). Determine the equation of the curve.

start with the distance formula, $\displaystyle \sqrt{(x_1-x_2)^2 + (y_1-y_2)^2}$ ...

$\displaystyle \sqrt{(x+1)^2 + (y-1)^2} = 3\sqrt{(x-2)^2+(y+1)^2}$