Find the value of `2cos((5pi)/12) cos(pi/12)` and `2sin((5pi)/12)cos(pi/12)`

Find the value of: cos((5pi)/12)

cos(pi/12)+sin^2((3pi)/12)+sin^2((9pi)/12)+cos((11pi)/12)=...

(sin((5pi)/12)-cos((5pi)/12))/(cos((5pi)/12)+sin((5pi)/12))=

Find the value of cos""(pi)/(12)(sin""(5pi)/(12)+cos""(pi)/(4))+sin""(pi)/(12)(cos""(5pi)/(12)-sin""(pi)/(4)) .

Find the value of cos""(pi)/(12)(sin""(5pi)/(12)+cos""(pi)/(4))+sin""(pi)/(12)(cos""(5pi)/(12)-sin""(pi)/(4)) .

Prove that cos(pi/12)+cos(3pi/12)+cos(9pi/12)+cos(11pi/12)=0

The value of "cos"^(2)(pi)/(12)+"cos"^(2)(pi)/(4)+"cos"^(2)(5pi)/(12) is

THe value of cos^(2)((pi)/(12))+cos^(2)((pi)/(4))+cos^(2)((5 pi)/(12)) is

(cos(pi/12)-sin(pi/12))(tan(pi/12)+cot(pi/12))=

2sin((5 pi)/(12))(sin((pi)/(12)))=