symprod

$$\begin{array}{l}P1={\displaystyle \underset{k=2}{\overset{\infty }{\prod }}1-\frac{1}{k^2}},\\ P2={\displaystyle \underset{k=2}{\overset{\infty }{\prod }}\frac{k^2}{k^2-1}}。\end{array}$$

$$P={\displaystyle \underset{k=1}{\overset{\mathrm{10000年}}{\prod }}\frac{e^{kx}}{x}}。$$

$$\begin{array}{l}P1={\displaystyle \underset{k}{\prod }k},\\ P2={\displaystyle \underset{k}{\prod }\frac{2k-1}{k^2}}。\end{array}$$