## Linux and UNIX Man Pages

Test Your Knowledge in Computers #1011
Difficulty: Easy
The number 128 in base 10 equals 10000000 in base 2.
True or False?

# tan(3m) [opensolaris man page]

```tan(3M) 						  Mathematical Library Functions						   tan(3M)

NAME
tan, tanf, tanl - tangent function

SYNOPSIS
c99 [ flag... ] file... -lm [ library... ]
#include <math.h>

double tan(double x);

float tanf(float x);

long double tanl(long double x);

DESCRIPTION
These functions compute the tangent of their argument x, measured in radians.

RETURN VALUES
Upon successful completion, these functions return the tangent of x.

If x is NaN, a NaN is returned.

If x is +-0, x is returned.

If x is +-Inf, a domain error occurs and a NaN is returned.

ERRORS
These functions will fail if:

Domain Error    The value of x is +-Inf.

If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, the invalid floating-point exception is raised.

USAGE
There are no known floating-point representations such that for a normal argument, tan(x) is either overflow or underflow.

An  application	wanting  to  check  for  exceptions should call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if
fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an exception  has  been  raised.  An  application  should
either examine the return value or check the floating point exception flags to detect exceptions.

ATTRIBUTES
See attributes(5) for descriptions of the following attributes:

+-----------------------------+-----------------------------+
|      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
+-----------------------------+-----------------------------+
|Interface Stability	     |Standard			   |
+-----------------------------+-----------------------------+
|MT-Level		     |MT-Safe			   |
+-----------------------------+-----------------------------+