Certain elliptic functions, such as the theta functions, traditionally use the nome
as their argument; others use the modulus
. InverseEllipticNomeQ returns the modulus corresponding to a given nome. This function is inverse to EllipticNomeQ.
The range of EllipticNomeQ is illustrated in the Further Examples for that function. InverseEllipticNomeQ can be extended outside this range. Thus extended, it is no longer a one-to-one function, and so not strictly an inverse to EllipticNomeQ.
It is a good idea to use multiple precision when the argument is a real number greater than 1/2.