The inverse hyperbolic functions may be found geometrically by reflecting the hyperbolic functions of Fig. 64 in the line y/x . As the hyperbolic sine, cosecant, tangent and cotangent functions are one/one they will have unique inverses. These are denoted, respectively, by arsinh x , arcosech x , artanh x
and arcoth x or, alternatively, by sinh1 x , cosech1 x , tanh1 x and
coth1 x .