De-montrer-que-n-1-1-n-1-n-4-1-2-pi-2-sin-pi-2-cosh-pi-2-sinh-pi-2-cos-pi-2-sinh-2-pi-2-sin-2-pi-2-

Question Number 133910 by Ar Brandon last updated on 25/Feb/21

D \overset{´}{e m o n t r e r} que;

\underset{n = 1}{\sum^{\infty}} \frac{{(- 1)}^{n}}{1 + n^{4}} = \frac{1}{2} [\frac{π}{\sqrt{2}} \frac{\sin (\frac{π}{\sqrt{2}}) \cosh (\frac{π}{\sqrt{2}}) + \sinh (\frac{π}{\sqrt{2}}) \cos (\frac{π}{\sqrt{2}})}{\sinh^{2} (\frac{π}{\sqrt{2}}) + \sin^{2} (\frac{π}{\sqrt{2}})}]