Upper bound of ${\psi }_n^{\left(1\right)}\left(u\mathrm{,}\alpha \mathrm{,}M\right)$

$\left(\alpha =0.350000,M=1.103245\right)$

0.002537

$\left(\alpha =0.508604,M=1.903245\right)$

0.005140

$\left(\alpha =0.758614,M=2.403446\right)$

0.006472