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

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

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

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 values of :b. tan^2 30^@+tan^2 45^@+tan^2 60^@

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

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

Show that : tan^-1 3+tan^-1 4-tan^-1(-7/11)=pi

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