Maximum Height 

It is the particle’s highest point (point A). The vertical component of the velocity (V_y) will be zero when the ball reaches point A. 

That is, 0 = (usinθ)² – 2gH_max      

( S = H_max, v_y = 0 and u_y = u sin θ )

The Maximum Height of the projectile is:

Maximum Height (Hmax) = u2sin2θ/2g