3. The distance "R" a ball travels is given by
R= 2VxVz/g where Vx is the horizontal velocity and Vz is the vertical velocity. Maximize R over all velocities (Vx,Vz),(square root of V2/x + V2/z = s, to show that the best trajectory is 45 degrees.
The solution determines the distance that the ball travels, and shows that the best trajectory is 45 degrees.