Reference
C Library
IOstream Library
Strings library
STL Containers
STL Algorithms
Miscellaneous
C Library
cassert (assert.h)
cctype (ctype.h)
cerrno (errno.h)
cfloat (float.h)
ciso646 (iso646.h)
climits (limits.h)
clocale (locale.h)
cmath (math.h)
csetjmp (setjmp.h)
csignal (signal.h)
cstdarg (stdarg.h)
cstddef (stddef.h)
cstdio (stdio.h)
cstdlib (stdlib.h)
cstring (string.h)
ctime (time.h)
cmath (math.h)
functions:
abs
acos
asin
atan
atan2
ceil
cos
cosh
exp
fabs
floor
fmod
frexp
ldexp
log
log10
modf
pow
sin
sinh
sqrt
tan
tanh
macro constants:
HUGE_VAL


tan

function
<cmath> 
     double tan (      double x );
      float tan (       float x );
long double tan ( long double x );

Compute tangent

Returns the tangent of an angle of x radians.

In C++, this function is overloaded in <complex> and <valarray> (see complex tan and valarray tan).

Parameters

x
Floating point value representing an angle expressed in radians.

Return Value

Tangent of x.

Portability

In C, only the double version of this function exists with this name.

Example

1
2
3
4
5
6
7
8
9
10
11
12
13
14
 
/* tan example */
#include <stdio.h>
#include <math.h>
#define PI 3.14159265
int main ()
{
  double param, result;
  param = 45.0;
  result = tan (param*PI/180);
  printf ("The tangent of %lf degrees is %lf.\n", param, result );
  return 0;
}


Output:

The tangent of 45.000000 degrees is 1.000000.

See also

sin Compute sine (function)
cos Compute cosine (function)
atan Compute arc tangent (function)