value of Dirichlet eta function at
The value
of the Dirichlet eta function can be found by using the Fourier cosine series
of the function
on the interval :
(1) |
Substituting to the equation (1) yields
which we can solve to the form
(2) |
This result could be obtained very simply by using the functional equation connecting Dirichlet eta function to Riemann zeta function.
Combining the equation (2) with the result concerning the Riemann zeta function at 2 (http://planetmath.org/ValueOfTheRiemannZetaFunctionAtS2) shows that
(3) |