2^x - 2^(3-x) =7
x=3
中間步驟係點???
quadratic equation
2010-06-06 7:58 am
回答 (2)
2010-06-06 8:09 am
2010-06-06 8:11 am
y=2^x
y-8/y=7
y^2-7y-8=0
y=8 or -1 (rejected, as log(-1) undefined)
2^x=8
x=3
May not need to let y, just for easy typing
y-8/y=7
y^2-7y-8=0
y=8 or -1 (rejected, as log(-1) undefined)
2^x=8
x=3
May not need to let y, just for easy typing
收錄日期: 2021-04-23 20:48:52
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100605000051KK01843