Find power series for e^3x.cos(2x) as far as the term x^2. My answer is f(0)+f'(0)x+(1/2)f''(0)x2=1+3x+(5/2)x2. Is this correct?

Question

anonymous · Answer

Did you try using the explicit formulas for $\exp (3x)$ and $\cos(2x)$ and use the Cauchy Product? Applying point wise differentiation seems to be a bit tedious, if you simply want to verify/falsify your answer I recommend you to use a computational engine like WolframAlpha

anonymous · Answer

http://www.wolframalpha.com/input/?i=+e%5E%283x%29*cos%282x%29 For computational exercises you should get used to use software like that.

anonymous · Answer

thank you, good tool to use