cc [ flag ... ] file ... -lm [ library ... ] #include <math.h>
The tan() function computes the tangent of its argument x, measured in radians.
Upon successful completion, tan() returns the tangent of x.
If x is NaN or +-Inf, NaN is returned.
No errors will occur.
See attributes(5) for descriptions of the following attributes:
atan(3M), isnan(3M), attributes(5)