Format
#include <builtin.h> double _fptan(double x);
Language Level: Extension
_fptan calculates the tangent of x,
where is x expressed in radians. The value of x must
be less than 2**63. This function causes the compiler to emit the
appropriate 80387 instruction for the calculation of tangent.
Because it is a built-in function and has no backing code in the library:
Return Value
_fptan returns the tangent of x
expressed in radians.
Example
This example calculates the tangent of
PI/4.
#include <builtin.h> #include <stdio.h>
int main(void)
{
double pi;
pi = 3.1415926;
printf("The tangent of %lf is %lf.\n", pi/4.0, _fptan(pi/4.0));
return 0;
/***************************************************************
The output should be:
The tangent of 0.785398 is 1.000000. ***************************************************************/ }
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atan - atan2 -- Calculate
Arctangent
_fpatan --
Calculate Arctangent
tan -- Calculate
Tangent
tanh -- Calculate
Hyperbolic Tangent
<builtin.h>