tan20*tan30*tan40*tan80=1

Without using Trigonometric Tables evaluate the following :- (sin^2 35^@+sin^2 55^@)/(tan10^@tan20^@tan30^@tan70^@tan80^@) .

tan 10^(@)*tan20^(@)*tan30^(@)*tan40^(@)*tan50^(@)*tan60^@tan70^(@)*tan80^(@)=

tan20^@tan40^@tan60^@tan80^@=

Prove that tan20^0tan40^0tan80^0=tan60^0

Prove that: tan20^0tan40^0tan80^0=tan60^0

Prove that tan20^0tan40^0tan60^0tan80^0 =3

Prove that tan20^0tan40^0tan80^0=tan60^0

Show that tan20^@tan40^@tan80^@=sqrt3

If tan20^0+tan40^0+tan80^0-tan60^0 = lambdasin40^0 , find lambda.

Prove that: t a n 20^0tan40^0tan60^0tan80^0=3