I'm making a simple game where I shoot things from a certain point on screen (A).

I tap the screen and shoot the projectile from initial point(A) to the tap point(B).

But I want the projectile to move along the same path instead and fly out of bounds of the screen.

How do I calculate a point that is on the same line that these two points, but further away?

This is a simple math, but I can't figure it out.