ζ⁡(1-s,x)=Γ⁡(s)(2⁢π)s⁢(ⅇ-π⁢ⅈ⁢s/2⁢F⁡(x,s)+ⅇπ⁢ⅈ⁢s/2⁢F⁡(-x,s)),