Please somebody provide a proof in detail to this problem. I have tried it many times but no sucess so far.
Let $$ \frac{\pi\alpha} 2 = \log\tan\left( \frac \pi 4 (1+\beta) \right). $$ Then $$ \left( \frac{1^2+\alpha^2}{1^2-\beta^2} \right)\left( \frac{3^2-\beta^2}{3^2+\alpha^2} \right)^3 \left( \frac{5^2+\alpha^2}{5^2-\beta^2} \right)^5 \cdots = e^{(\pi/2)\alpha\beta}. $$