Need a refresher on partial differentiation and gradients for energy problems?

[plutoisacomet]

Hello guys, My class is heading into energy with non-conservative and conservative forces. I am not in Calc this semester so is there a guide to partial differentiation and gradients that you can share with me to get up to speed?
Thanks

 

[Doc Al]

Try this: http://www.math.hmc.edu/calculus/tutorials/partialdifferentiation/

 

[plutoisacomet]

Thanks Doc Al that link is very helpful. I can do my energy problem sets now.
Many thanks.