PA^2+PB^2=4 where A=(3,-1) and B=(-5,4). Find the equation of the locus of P.
Find the equation of the locus of a point that moves so that its distance from the line 3x+4y+5=0 is always 4 units.
Find the equation of the locus of a point that moves so that it is equidistant from the line 3x+4y-5=0 and the line 5x+12y-1=0.