Expand sin(x)sin(2x) as far as the term in x^(3)
I want to know the FASTEST method.
Please show the steps.
Thank you very much!!!
Maclaurin's expansion
2012-12-02 4:55 am
回答 (1)
2012-12-02 6:11 am
✔ 最佳答案
sin x = x - x^3/3! + x^5/5! - ....sin 2x = 2x - (2x)^3/3! + (2x)^5/5! - ...
sin x * sin 2x
= (x - x^3/3! + x^5/5! - ...)(2x - (2x)^3/3! + (2x)^5/5! - ...)
= 2x^2 (as far as the term in x^3)
收錄日期: 2021-04-27 17:43:08
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