Find the exact value of the expression `(tan70^@-tan20^@-2tan40^@)/tan10^@`

Find the exact value of the expression tan(pi/20)-tan((3pi)/20)+tan((5pi)/20)-tan((7pi)/20)+tan((9pi)/20).

Find the exact value of the expression tan(pi/20)-tan((3pi)/20)+tan((5pi)/20)-tan((7pi)/20)+tan((9pi)/20).

Find the exact value of the expression tan((pi)/(20))-tan((3 pi)/(20))+tan((5 pi)/(20))-tan((7 pi)/(20))+tan((9 pi)/(20))

tan10^(@)-tan50^(@)+tan70^(@)

Prove that tan70^@=tan20^@+2tan50^@

The value of (tan70^@-tan20^@)/(tan50^@)=

Prove that tan 70^(@)-tan 20^(@)-2 tan 40^(@)=4 tan 10^(@)

tan20^@+tan40^@+sqrt3tan20^@tan40^@=

(tan80^(@)-tan10^(@))/(tan70^(@))

(tan80^(@)-tan10^(@))/(tan70^(@))