• Guo, Bai-Ni ;
  • Qi, Feng
  • Published : 2010.01.31


In the present paper, we give two new proofs for the necessary and sufficient condition $\alpha\leq1$ such that the function $x^{\alpha}[lnx-\psi(x)]$ is completely monotonic on (0,$\infty$).


new proof;completely monotonic function;psi function;inequality


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