" (ii) "tan^(-1)(tan15)

Write the value of tan^(-1){tan((15pi)/4)}

Write the value of tan^(-1){tan((15pi)/4)}

Value of cos{tan^(-1) ("tan"(15pi)/4)} is :

Write the value of "tan"^(-1)["tan"((15pi)/(4))] .

(i) cos 15^@ (ii) cos75^@ (iii) tan15^@ (iv)tan75^@

cos[tan^(-1){tan((15pi)/4)}]

cos[tan^(-1){tan((15pi)/4)}]

Evaluate sin (50^(@) + theta) - cos (40^(@) - theta) + tan 1^(@) tan 15^(@) tan 20^(@) tan 70^(@) tan 65^(@) tan 89^(@) + sec (90^(@) - theta). cosec theta - tan (90^(@) - theta ) cot theta

1/3gt0,3/4gt0impliestan^(-1)(1/3)-tan^(-1)(3/4) =tan^(-1)((1/3-3/4)/(1+1/3 . 3/4))=tan^(-1)((-5)/15)=tan^(-1)(1/3) =-tan^(-1)(1/3)

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