ok so i got this equation, and i got an answer, but its different than my friends, and we really are starting to doubt both our answers, so i thought the best place to go would be the student room
don't let me down please..
dy of (e^x/5)sin(2x) - (2e^x/5)cos(2x)
i decided to use product rule seperately on each part, and i ended up with
e^x(5sin(2x) + cos(2x))
as in the top line all divided by 5... i can't remember what my friend got off the top of my head. can anyone tell me what i should have done/ if i am right?
thanks in advance
pos rep for a sufficiently informative answer
Differentiation help please! Watch
- Thread Starter
- 19-01-2010 20:18
- 19-01-2010 20:22
do you mean e^(x/5) or (e^x)/5??
- 19-01-2010 20:26
if you mean (e^x)/5 then the cos terms shoulds cancel.... and you are left with e^x(sin2x).... check your signs
- 19-01-2010 20:32
If you mean (e^(x/5))
Then make sure when you differentiate it, you get 0.2*(e^(x/5))
Also when you differentiate your Cos2X you get -2Sin2X and similar for Sin2X.