Without using trigonometric tables, prove that :
(i) `tan 48^@tan 23^@tan 42^@tan 67^@ =1`
(ii) `tan 7^@tan 23^@ tan 60^@ 67^@tan 83^@=sqrt(3)`
(iii) `cot 12^@cot 38^@cot 52^@cot 60^@cot 78^@=(1)/(sqrt(3))`

Show that : tan 48 ^@ tan 23^@ tan 42^@ tan 67 ^@ = 1

Show that : tan 48^@ tan 23^@ tan 42^@ tan 67^@ = 1

Show that : tan48^@tan23^@tan42^@tan67^@=1 .

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

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

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

Show that tan48^(@) tan 23^(@) tan 42^(@) tan 67^(@) =1 .

Show that tan48^(@) tan 23^(@) tan 42^(@) tan 67^(@) =1 .

Without using trigonometric tables , prove that : (i) tan20^(@)tan40^(@) tan45^(@)tan50^(@)tan70^(@)=1 (ii) tan1^(@) tan2^(@)tan60^(@)tan88^(@)tan89^(@)=sqrt(3) (iii) cot5^(@)cot10^(@)cot30^(@)cot80^(@)cot85^(@)=sqrt(3) (iv) 4sin10^(@)sin20^(@)sin30^(@)sec70^(@)sec80^(@)=2