Math Question. with solution. Thanks?
回答 (1)
2016-02-01 4:49 am
✔ 最佳答案
f(x) = x cos xf'(x) = (1) cos x + x (- sin x) = cos x - x sin x
f'(π) = cos π - π sin π = (-1) - π (0) = -1
∴ D. -1
收錄日期: 2021-04-18 14:22:54
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https://hk.answers.yahoo.com/question/index?qid=20160131195547AA0iXNO