Manpages - cacosh.3

cacosh, cacoshf, cacoshl - complex arc hyperbolic cosine

  #include <complex.h>

  double complex cacosh(double complex z);
  float complex cacoshf(float complex z);
  long double complex cacoshl(long double complex z);

  Link with -lm.

These functions calculate the complex arc hyperbolic cosine of z. If y = cacosh(z), then z = ccosh(y). The imaginary part of y is chosen in the interval [-pi,pi]. The real part of y is chosen nonnegative.

One has:

      cacosh(z) = 2 * clog(csqrt((z + 1) / 2) + csqrt((z - 1) / 2))

These functions first appeared in glibc in version 2.1.

For an explanation of the terms used in this section, see *attributes*(7).

C99, POSIX.1-2001, POSIX.1-2008.

  /* Link with "-lm" */

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

  int
  main(int argc, char *argv[])
  {
      double complex z, c, f;

      if (argc != 3) {
          fprintf(stderr, "Usage: %s <real> <imag>\n", argv[0]);
          exit(EXIT_FAILURE);
      }

      z = atof(argv[1]) + atof(argv[2]) * I;

      c = cacosh(z);
      printf("cacosh() = %6.3f %6.3f*i\n", creal(c), cimag(c));

      f = 2 * clog(csqrt((z + 1)/2) + csqrt((z - 1)/2));
      printf("formula  = %6.3f %6.3f*i\n", creal(f2), cimag(f2));

      exit(EXIT_SUCCESS);
  }

*acosh*(3), *cabs*(3), *ccosh*(3), *cimag*(3), *complex*(7)

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