On a trigonometric inequality of Askey and Steinig
Horst Alzer, Man Kam Kwong · Asymptotic Analysis · 2018
In 1974, Askey and Steinig showed that for [Formula: see text] and [Formula: see text], [Formula: see text] We prove that [Formula: see text] and that the alternating sums [Formula: see text] satisfy [Formula: see text] Both inequalities hold for all [Formula: see text] and [Formula: see text]. The constant lower bounds given in ( 0.1 ) and ( 0.2 ) are best possible. The asymptotic behaviour of both sums is also investigated.