" The value of "tan6^(@)tan42^(@)tan66^(@)tan78^(@)" is "

The value of tan 6^(@) tan 42^(@) tan 66^(@) tan 78^(@) is

Prove that tan A. (tan 60^(@) +A). Tan (60^(@)-A)=tan 3A and hence find the value of tan 6^(@) tan 42^(@) tan 66^(@) tan 78^(@) .

tan 6 ^(@) tan 42 ^(@) tan 66 ^(@) tan 78^(@) =1

The value of tan^(-1)tan(-6) is

The value of tan^(-1)tan(-6) is

Prove that: tan6^(0)tan42^(0)tan66^(@)tan78^(@)=1

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