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

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 tan69+tan66-tan69tan66=2k then k=

If tan69^(@)+tan66^(@)=2k, then k=-1b1/2c.-1/2d.17

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

Prove tan 9^@. tan 21^@.tan 69^@.tan 81^@=1

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

Show that tan6^@tan42^@tan66^@tan78^@=1

Prove that tan6^@tan42^@tan66^@tan78^@=1

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