### _fsincos -- Calculate Sine and Cosine

Format

>     #include <builtin.h>
>     double _fsincos(double x, double *y);

Language Level: Extension
_fsincos calculates the sine of x, and stores the cosine in *y. This operation is faster than separately calculating the sine and cosine. Use _fsincos instead of _fcossin when you will be using the sine first, and then the cosine.

Because it is a built-in function and has no backing code in the library:

- You cannot take the address of _fsincos.
- You cannot parenthesize a _fsincos function call because parentheses specify a call to the backing code for the function.

Return Value
This function returns the sine of x.

Example
This example calculates the sine of x and stores it in z, and stores the cosine of x in y.

    #include <builtin.h>
    #include <stdio.h>

    int main(void)
    {
       double x, y, z;

       printf("Enter x:\n");
       scanf("%lf", &x);

       z = _fsincos(x, &y);
       printf("The sine of %lf is %lf.\n", x, z);
       printf("The cosine of %lf is %lf.\n", x, y);
       return 0;

       /***********************************************
          Assuming you enter: 1.0

          The output should be:

          The sine of 1.000000 is 0.841471.
          The cosine of 1.000000 is 0.540302.
       ***********************************************/
    }

acos -- Calculate Arccosine
asin -- Calculate Arcsine
cos -- Calculate Cosine
cosh -- Calculate Hyperbolic Cosine
_facos -- Calculate Arccosine
_fasin -- Calculate Arcsine
_fcos -- Calculate Cosine
_fcossin -- Calculate Cosine and Sine
_fsin -- Calculate Sine
sin -- Calculate Sine
sinh -- Calculate Hyperbolic Sine
<builtin.h>