Rifleman's Rule: Best angle for a projectile up a hill [urgent] 1. The problem statement, all variables and given/known data A projectile is fired at speed Vo at an elevation angle alpha up a hill of slope beta (alpha>beta). At what angle will the range (L) be maximum? 2. Relevant equations L=(2Vo^2)/g*(cos(a)/cos(b))*(sin(a)-cos(a)tan(b)) is the distance up the slope that 3. The attempt at a solution From the above equation we can see that if b=zero, we can maximize the equation by making a=45. If a=b, L=0. The question is, how do we make an equation that maximizes L. I tried integrating and setting the LHS to zero, but that didn't work. I need a relationship between L, b, and a that maximizes. I'd like no full answers here since it is a homework question, just help as to how to find the relationship.