Inverse error function (SymPy, WMA)
InverseErf
InverseErf /@ {-1, 0, 1}
Plot[InverseErf[x], {x, -1, 1}]
InverseErf[z] only returns numeric values for -1 <= z <= 1:
InverseErf[z]
-1 <= z <= 1
InverseErf /@ {0.9, 1.0, 1.1}