Evaluate tan `15^(@)`.

Evaluate : tan 25^(@) tan 65 ^(@) - cot 25^(@) cot 65^(@)

Evaluate (tan60^(@)-tan30^(@))/(1+tan60^(@)tan30^(@)) .

Evaluate tan20^(@)tan25^(@)tan65^(@)tan70^(@) .

Evaluate : tan7^(@)tan23^(@)tan60^(@)tan67^(@)tan83^(@)+(cot54^(@))/(tan36^(@))+sin20^(@)sec70^(@)-2

Evaluate tan^(-1).(1)/(2)+ tan^(-1).(1)/(3) .

Find the value of tan15^(0)

Without using trigonometric tables , evaluate : ((tan20^(@))/(cosec70^(@)))^(2)+((cot20^(@))/(sec70^(@)))^2+2tan 15^(@)tan37^(@)tan53^(@)tan60^(@)tan75^(@)

Evaluate tan^(-1)(tan128^(@))

Evaluate: tan^(-1)(1)+tan^(-1)(0),

Evaluate tan 40^@ xx tan 50^@