" 11) "quad (tan69+tan66)/(1-tan69tan66)=-1

Prove that (tan69^@+tan66^@)/(1-tan69^@tan66^@)=-1 .

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

If tan69+tan66-tan69tan66=2k then k=

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

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

Prove that (tan69^(@)+tan66^(@))/(1-tan69^(@)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

Prove that : tan 69^@ + tan 66^@+ 1 = tan 69^@ tan 66^@ .

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

tan(A+B)=(tan A+tan B)/(1-tan A tan B)