(tan69^(@)+tan66^(@))/(1-tan69^(@)tan66^(@))=-1

Prove that :(tan69^@+tan 66^@)/(1-tan 69^@tan66^@)=-1

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

Simplify be reducing to a single term : (tan 69^(@) + tan 66^(@))/(1 - tan 69^(@) tan 66 ^(@))

If tan 69^(@) + tan 66^(@) - tan 69^(@)tan 66^(@) = 2k then k = (a) -(1)/(2) (b) (1)/(2) (c) -1 (d)None of these

Prove that:(i) "tan"69^(@)+"tan"66^(@)+1="tan"69^(@) "tan"66^(@) (ii) (cos13^(@)+"sin"13^(@))/(cos13^(@)-"sin"13^(@))="tan"58^(@)

If tan 69^(@) + tan 66^@ - tan 69^(@) tan66^@=2k , then the value of k is

If (tan69^0+t a n 66^0) /(1-tan69^@tan66^@)=2k ,\ t h e n\ k= -1 b. 1//2 c. -1//2 d. 17

If (tan46^(@)-tan1^(@)-1)(tan47^(@)-tan2^(@)-1)(tan48^(@)-tan30^(@)-1)...(tan89^(@)-tan44^(@)-1), then find the value of n.

Prove that : tan1^(@)tan11^(@)tan21^(@)tan69^(@)tan79^(@)tan89^(@)=1