_chi _ci _shi _si

_si() double _si ( double  x ) Sine integral Si(x) Purpose si computes the sine integral. Si(x) = ∫ sin(t)/t dt [0, x] Returns Sine integral Si(x). Parameters [in] x Argument x. Error handling If x is NaN, NaN is returned and errno is not altered. Range error (ERANGE) may occur.