Ok, I have another problem that's bugging me pretty badly.

Find the derivative:

y=13t^2+40sqrt(t)+15/t

I know that the derivative of 13t^2 = 26t

but I'm unsure about what to do with the 40sqrt(t).

Would it be something like:

(.5)40x^-.5=1/20x?

but then what about 15/t?