Where's the inverse of Math.tanh in the math libraries?

Question

y = Math.Tanh(x) is the hyperbolic tangent of x. But I need f(y) = x. For the regular tangent there\'s Arctan, but where\'s Arctanh?

Answer 1

I installed MathNet from the package manager. It has MathNet.Numerics.Trig.InverseHyperbolicTangent(x) which works well enough.