摘要:
$$\Large\displaystyle \int_0^{\pi/2}\ln^2(\sin x)\ln(\cos x)\tan x \,{\rm d}x$$ $\Large\mathbf{Solution:}$ Let $J$ donates the integral and it is easy 阅读全文
摘要:
$$\Large\displaystyle \sum_{n=1}^{\infty}\frac{H_{2n}}{n(6n+1)}$$ $\Large\mathbf{Solution:}$ Let $S$ denote the sum. Then $$\begin{align } S=\sum_{n=1 阅读全文
摘要:
$$\Large\displaystyle \sum_{n=1}^{\infty} \frac{\widetilde{H_n}}{n^{3}}$$ where $\widetilde{H_n}$ is the alternating harmonic number. $\Large\mathbf{S 阅读全文