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1. 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

ok so

find...

dy of (e^x/5)sin(2x) - (2e^x/5)cos(2x)
dx

i decided to use product rule seperately on each part, and i ended up with

e^x(5sin(2x) + cos(2x))
5

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?

pos rep for a sufficiently informative answer
2. do you mean e^(x/5) or (e^x)/5??
3. if you mean (e^x)/5 then the cos terms shoulds cancel.... and you are left with e^x(sin2x).... check your signs
4. 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.

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Updated: January 19, 2010
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