Question

in projectile motion, the initial horizontal velocity is ...... the final horizontal velocity. (what is the blank)

Answer 1

The horizontal acceleration is always zero for this problem ( ax = 0), because there are no forces acting in horizontal direction.
Therefore Vx = const
and in projectile motion, the initial horizontal velocity is equal to (the same as) the final horizontal velocity

Answer: in projectile motion, the initial horizontal velocity is equal to (the same as) the final horizontal velocity