1. ## equation of locus

Derive the equation of the locus of all points whose distance to the point F(-5,4) is half the distance to the line y = -4. Leave your answer in general form.

2. Originally Posted by Mr_Green
Derive the equation of the locus of all points whose distance to the point F(-5,4) is half the distance to the line y = -4. Leave your answer in general form.
Distance from a point requires the distance formula.

If points are (a,b), then the distance is: $\sqrt{(a-(-5))^{2}+(b-4)^{2}}$

Distance from the line y = -4 is simply b - (-4)

A little algebra and you're done. Do you recognize it with a familiar name??