[Tidus810]

I haven't had to do any of this recent enough to be 100% sure about how your work came out, but a lot of it looks correct. I can tell you, though, that for part of the derivative for Q2 you made a boo boo:
When you did the Chain Rule for 10xcos(5x), you got for the second term:
(10x(-sin(5x)+5cos(x)))
when actually I think it's:
-50xsin(5x)
which comes from 10x * -5sin(5x)

Hope this helps, if only a tiny bit.