" (iii) "cos306^(@)+cos234^(@)+cos162^(@)+cos18^(@)=0

Prove that cos306^(@) + cos234^(@) + cos162^(@) + cos18^(@) = 0

Prove: (iv) cos 306^(@) + cos 234^(@) + cos 162^(@) + cos 18^(@) = 0 .

cos130^(@)+cos110^(@)+cos10^(@)=0

cos130^(@)+cos110^(@)+cos10^(@)=0

What is the value of cos306^(@)+cos234^(@)+cos162^(@)+cos18^(@) ?

cos42^(@)+cos78^(@)+cos162^(@)=

cos 20^(@) + cos 100^(@) + cos 140^(@) = 0

Prove that: cos20^(0)cos100^(@)+cos100^(@)cos140^(@)-cos140^(@)-cos140^(@)cos200^(@)=

A=sin78^(@)-sin18^(@)+cos132^(@) B=cos12^(@)+cos84^(@)+cos132^(@)+cos156^(@) and C=(sin 75^(@)+sin 15^(@))/(cos 75^(@)+cos 15^(@)) then arrange in the ascending order