Well it's not clear what the expression is. Use LaTeX. If the expression is what I think it is, then you haven't done anything at all to it.
I have no idea what you mean by this! it is certainly NOT the function above. Did you mean that as f'(x)? It is not for either or .f(x)=e^x(2/3sin(x) (2/3sin(x))
If you meant , its derivative is itself, times the derivative of which is NOT .=e^x(2/3sin(x) 2/3cos(x)
I'm stuck on trying to differentiate f(x)=e^x(2/3sin x) as well and I've tangled myself up into a complete mind block! I think it's the 2/3 aspect confusing me the most, I've never been quite sure what to do with fractions when they pop up like this in functions. D'oh. Any help/advice would be much appreciated!