[cos105^(@)+sin105^(@)],[" IS "]

105^(2)

cos15^(@)+cos105^(@)=

sin105^(@)+cos105^(@)=

sin15^(@)+cos105^(@)=?

The value of cos 105^@ + sin 105^@ is

cos 15^@+ cos 105^@ =?

sin 15^(@) + cos 105 ^(@) =

sin 15^(@) + cos 105 ^(@) = ............ A) 0 B) 2 sin 15 ^(@) C) cos 15^(@) + sin 15^(@) D) sin 15^(@) - cos 15^(@)

Prove that (i) "cos " 15^(@) - " sin " 15^(@) = (1)/(sqrt(2)) (ii) " cot " 105^(@) - " tan " 105^(@) =2sqrt(3) (iii) (tan 69^(@) + tan 66^(@))/(1-tan 69^(@) tan 66^(@)) =-1