I dont have a clue how people come up to the second part of the equation after the equal sign... please help me to understand!

- Sep 2nd 2010, 09:16 AMprobladyexp^x-exp^-x / exp^x+exp^-x=exp^2*x-1/exp^2*x+1 --> hyperbolic tangent
I dont have a clue how people come up to the second part of the equation after the equal sign... please help me to understand!

- Sep 2nd 2010, 09:21 AMAckbeet
Just multiply top and bottom by .

- Sep 2nd 2010, 12:05 PMproblady
but why to do that? could you explain

- Sep 2nd 2010, 12:25 PMAckbeet
I'm not exactly sure myself. If I wanted to prove the identity, I would do this:

It depends on how you define the hyperbolic tangent function, I guess. Make sense? - Sep 2nd 2010, 12:54 PMArchie Meade
,

one of the countless ways to express the value 1.

Therefore...

giving a reduced form of tanh(x)

Hyperbolic function - Wikipedia, the free encyclopedia