dy/dx
2009-03-23 10:38 am
圖片參考：http://i283.photobucket.com/albums/kk288/byfrgnhvt/001-1.gif
My answer is:
圖片參考：http://i283.photobucket.com/albums/kk288/byfrgnhvt/222.gif
Is correct ?
回答 (1)
2009-03-23 3:49 pm
✔ 最佳答案
Q1.y' = [(1 + e^t)d(t + sin t) - (t + sin t) d(1 + e^t)]/(1 + e^t)^2
= [(1 + e^t)(1 + cos t) - (t + sin t)(e^t)]/(1 + e^t)^2
= [(1 + cos t) + e^t + e^t cos t - t e^t - e^t sin t]/( 1 + e^t)^2
= [ 1 + cos t + e^t( 1 + cos t - sin t - t)]/(1 + e^t)^2.
Note : e^t is missing in your answer.
Q2. is correct.
收錄日期: 2021-04-25 22:40:08
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090323000051KK00157