maths e

👨🏻‍🏫 學術台數學

Grace

2010-10-30 6:24 am

Given e^x + e^-x =20, find e^2x - e^-2x

explain in clear steps please

回答 (2)

用戶9112

2010-10-30 6:36 am

✔ 最佳答案

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2010-10-29 22:36:50 補充：
http://img816.imageshack.us/img816/9321/58828930.png

2010-10-30 00:03:28 補充：
Yes, e^x - e^-x should be +/-6sqrt(11)
So e^2x - e^-2x is +/- 120 sqrt(11)

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用戶2053

2010-10-30 6:59 am

自由自在( 知識長 ) :

- 120√11 is another answer or not ?

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