Guardian Native C Library Calls Reference Manual (G06.28+, H06.05+)

Guardian Native C Library Calls (t - z) tan(3)
The XPG4 Version 2 specication leaves some features to the implementing vendor to dene.
The following features are affected in the HP implementation:
For IEEE oating-point data, errno is not set to [EDOM] when the value of x is NaN.
errno is not set to [ERANGE] when underow occurs.
The tan( ) function cannot cause overow so HUGE_VAL is not returned and errno is
not set to [ERANGE].
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