Two things regarding hyperbolic tangent (tanh(x)):
1) What is the inverse function of tanh(x)?
Apparently it is NOT artanh(x).
I need to know how to "undo" a tanh(x) function. Please help.
2) In my grapher, artanh(1) does not exist (is undefined, invalid or whatever).
Yet when I plug in artanh(sin(x)^2+cos(x)^2), which should be the same, I get weird splotches.
Is the grapher getting confused, or does there really exist a difference between 1 and sin(x)^2+cos(x)^2 vis-a-vis artanh(x)?