Question

Please help. I am lost

Answer 1

Explanation:

directrix is x=-4

or x+4=0

let (x,y) be any point on the parabola.

distance of (x,y) from (-1,15) is

`=√((x+1)^2+(y-15)^2)`

distance of (x,y) from x+4=0 is

`=(x+4)/(√(1) ) \\=(x+4)`

so

`x+4=√((x+1)^2+(y-15)^2) \\squaring\\x^(2) +8x+16=x^(2) +2x+1+(y-15)^2\\6x+15=(y-15)^2\\divide ~by~6\\x=(1)/(6) (y-15)^2-(5)/(2)`