range equation

[tman1]

My question is, derive an equation to find the maximum range of a projectile thats not on level ground. I am lost and i did attempt this, by making a diagram and subbing in what i thought i would need to use, but i still have not come up with the answer. plz help

[The Bob]

My question is, derive an equation to find the maximum range of a projectile thats not on level ground. I am lost and i did attempt this, by making a diagram and subbing in what i thought i would need to use, but i still have not come up with the answer. plz help
I think the best thing you can do is post whatever you have done. I could suggest a lot but I don't know what is making you go wrong.

The Bob (2004 ©)

[andrevdh]

Substitute
y=R\ sin\alpha
and
x=R\ cos\alpha
in the parabolic equation for the projectile.
The range will then be a function of \theta.The turning point of a function occurs where the derivative is zero...