cos〖(2π+α/4)-sin〖(2π+α/4)×ctg〖α/8〗/(cos〖(7π/2〗+α/4)+cos〖(α/4〗-3π)×ctg〖α/8〗 )=cos〖α/4-sin〖α/4×ctg〖α/8〗 /〖cos(〖π/2-α/4)+cos⁡〖(π-α/4)×ctg〖α/8〗 〗 〗 =cos〖α/4)-sin〖α/4)×ctg〖α/8〗 /(sin〖α/4)-cos〖α/4〗 ×ctg〖α/8〗 )=-tg〖α/8〗