# Thread: plaese solve the problem

1. ## plaese solve the problem

Prove that :

$
H= \sum_i p_i {\dot q_i} - L

$

2. That makes no sense at all. I could guess that p and q are "generalized coordinates" and that L is the Lagrangian (so this is a physics problem, not a math problem) but I have no idea what you want to solve for!

3. Thank you HallsofIvy
how this was derived?

4. Originally Posted by math22
Prove that :

$
H= \sum_i p_i {\dot q_i} - L

$
You will find the derivation in any textbook devoted to Classical Mechanics. I suggest you spend some time in the appropriate library of the institute you study at.

5. thanks
I did not find this proof in the curriculum, but this question got a zero ...
I proved $H=T+V$
Where $L=T-V$ and $\sum_i p_i {\dot q_i}=2T$

... No problem thank you again