S = rac{2(e^{i heta} + e^{-i heta} + e^{i\phi} + e^{-i\phi})}{e^{i heta} - e^{-i heta} - e^{i\phi} + e^{-i\phi}}.

Sat, 02 May 2026 10:54:33 +0000

Content under review