Using the results of Q26 and Q28, deduce the equality $$\forall x \in J, \quad \pi \tan(\pi x) = \sum_{p=1}^{+\infty} 2\left(2^{2p} - 1\right) \zeta(2p) x^{2p-1}$$
Using the results of Q26 and Q28, deduce the equality
$$\forall x \in J, \quad \pi \tan(\pi x) = \sum_{p=1}^{+\infty} 2\left(2^{2p} - 1\right) \zeta(2p) x^{2p-1}$$