Show that `1 -tan 10^@ -tan 35^@`=` tan 10^@ tan 35^@`

Show that : tan 50^@=tan 40^@+2tan 10^@ .

Prove tan 70^@=2tan 50^@+tan 20^@

Show that : tan^-1 4-tan^-1 3=cot^-1 13

tan10^@tan15^@tan75^@tan80^@ is

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

Find the values of tan 9^@-tan 27^@-tan 63^@ + tan 81^@

Without taking the help of the table of trigonometric ratios,show that:(ii) tan10^@tan15^@tan75^@tan80^@=1

Show that:(i) tan48^@tan23^@tan42^@tan67^@=1

Find the value : tan35^@tan60^@ tan55^@tan30^@

Prove that: tan 35° tan 40° tan 45° tan 50° tan 55° = 1 .