#ifndef STAN_MATH_FWD_SCAL_FUN_TAN_HPP
#define STAN_MATH_FWD_SCAL_FUN_TAN_HPP

#include <stan/math/fwd/core.hpp>

namespace stan {
  namespace math {

    template <typename T>
    inline
    fvar<T>
    tan(const fvar<T>& x) {
      using std::cos;
      using std::tan;
      return fvar<T>(tan(x.val_), x.d_ / (cos(x.val_) * cos(x.val_)));
    }
  }
}
#endif
