In this paper, we provide a systematic way to study on some general Wilker-Huygens type inequalities for the trigonometric and hyperbolic functions,
lemniscate and hyperbolic lemniscate functions, and their corresponding
inverse functions. Our results are some extensions and refinements of the
recently published results in [A. Mhanna, On a general Huygens-Wilker
inequality, Appl. Math. E.-Notes, 20 (2020), 79-81; MR4076436], and improve
many previous results involving Wilker-Huygens type inequalities.