(urgent)what is the integration for xcos2x dx?

👨🏻‍🏫 學術台數學

MandM

2011-10-25 1:18 pm

what is the integration for xcos2x dx?

and steps please.

回答 (3)

[匿名]

2011-10-25 1:27 pm

✔ 最佳答案

integration for xcos2x dx = (1/2)(sin 2x) + c

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[匿名]

2011-10-25 8:31 pm

â« xcos2x dx=Â½â« x d(sin2x)= Â½x*sin2x - Â½â« sin2x dx=
= Â½x*sin2x + Â¼cos2x+C

http://www.wolframalpha.com/input/?i=%E2%88%AB+xcos%282x%29+dx

參考: .

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[匿名]

2011-10-25 8:26 pm

The rule is: integration of cos(ax + b) = (1/a)[sin(ax + b)] +c
for you, a = 2 and b = 0 so...
the integral of xcos2x dx = (1/2)[sin2x] + c

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