R-果然翁

引用:

原帖由 Imisstime 於 2011-11-6 22:51 發表
2.{ [(e^x)-(e^-x)]/[(e^x)+(e^-x)]} x (e^x)
give (e^2x-1)/(e^2x+1)
Since (e^2x+1) is 份母

Try d/dx {ln(e^2x+1)}
and u will get  (2e^2x)/(e^2x+1)

Different between 2e^2x/(e^2x+1) and [(e^x)-(e^-x)]/[( ...

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