1 #ifndef STAN_MATH_REV_SCAL_FUN_ACOSH_HPP
2 #define STAN_MATH_REV_SCAL_FUN_ACOSH_HPP
10 #include <boost/math/special_functions/acosh.hpp>
18 class acosh_vari :
public op_v_vari {
20 acosh_vari(
double val, vari* avi) :
24 avi_->adj_ += adj_ /
std::sqrt(avi_->val_ * avi_->val_ - 1.0);
70 return var(
new acosh_vari(a.
val(), a.
vi_));
fvar< T > sqrt(const fvar< T > &x)
Independent (input) and dependent (output) variables for gradients.
var acosh(const var &a)
The inverse hyperbolic cosine function for variables (C99).
vari * vi_
Pointer to the implementation of this variable.
int is_inf(const fvar< T > &x)
Returns 1 if the input's value is infinite and 0 otherwise.
double val() const
Return the value of this variable.
fvar< T > acosh(const fvar< T > &x)