6.2.11 cacosl Function

Calculates the complex arc cosine function of a long double precision complex value.

Include

<complex.h>

Prototype

long double complex cacosl(long double complex z);

Argument

z

value for which to return the complex arc cosine

Return Value

Returns the complex arc cosine of z with no bound along the imaginary axis, in the interval $\mathrm{[0,\; \pi ]}$ along the real axis, and with branch cuts outside the interval $\mathrm{[-1,\; +1]}$ along the real axis.

Example

See the notes at the beginning of this chapter or section for information on using printf() or scanf() (and other functions reading and writing the stdin or stdout streams) in the example code.

#include <stdio.h>
#include <complex.h>

int main(void)
{
  long double complex x, y;

  x = -2.0 + 0.0*I;
  y = cacosl(x);
  printf("The complex arccosine of %Lf + %Lfi is %Lf + %Lfi\n", creall(x), cimagl(x), creall(y), cimagl(y));
}

Example Output

The complex arccosine of -2.000000 + 0.000000i is 3.141593 + -1.316958i