NAME acosh, acoshf - inverse hyperbolic cosine functions CONTENTS Library Synopsis Description Return Values See Also History LIBRARY .Lb libm SYNOPSIS .In math.h double acosh "double x" float acoshf "float x" DESCRIPTION The acosh and the acoshf functions compute the inverse hyperbolic cosine of the real argument x. For a discussion of error due to roundoff, see math(3). RETURN VALUES The acosh and the acoshf functions return the inverse hyperbolic cosine of x. If the argument is less than 1, acosh raises an invalid exception and returns an NaN. SEE ALSO asinh(3), atanh(3), exp(3), fenv(3), math(3) HISTORY
