FNEireturns the value of the exponential integral ofx, Ei(x). Ei(x) is defined by the relation
The integration represents the value obtained by integrating in the complex plane along a path that excludes the origin and that does not cross the negative part of the real axis. The value of Ei(x) is - atx= 0 and becomes large for large positive values ofx.
Ei(x)
Errors
FNEicauses an HTBasic error if its argument is not of type REAL or if the magnitude of Ei(x) would be greater than MAXREAL.