Show that the set of all points such that the difference of their distances from (4, 0) and (– 4, 0) is always equal to 2 represent a hyperbola.
Let the point be P (x,y)
According to the question
Distance of P from (-4,0) -Distance of P from (4,0)=2
Squaring both the sides
16x2-8x+1=x2+16-8x+y2
15x2-y2=15
Which is an equation of a hyperbola.