inv_sqrt() [7/7]

template<typename T , require_stan_scalar_or_eigen_t< T > * = nullptr>

auto stan::math::inv_sqrt ( const var_value< T > &  a )

inline

Template Parameters

T	Arithmetic or a type inheriting from EigenBase.

$$\mbox{inv\_sqrt}(x) = \begin{cases} \frac{1}{\sqrt{x}} & \mbox{if } -\infty\leq x \leq \infty \\[6pt] \textrm{NaN} & \mbox{if } x = \textrm{NaN} \end{cases}$$

$$\frac{\partial\, \mbox{inv\_sqrt}(x)}{\partial x} = \begin{cases} -\frac{1}{2\sqrt{x^3}} & \mbox{if } -\infty\leq x\leq \infty \\[6pt] \textrm{NaN} & \mbox{if } x = \textrm{NaN} \end{cases}$$

Definition at line 36 of file inv_sqrt.hpp.