" Q."15" If "tan70^(@)-tan20^(@)=k cot40^(@)" then "k" is "

tan 70^(@) - tan 20^(@)=

tan70 ^ (@) - tan20 ^ (@) = k cot40 ^ (@) rArr k =

If tan50^(@)-tan40^(@)=k tan10^(@) then the value of k is

tan 70^(@) - tan 20^(@) -2 tan 40^(@)=

tan 70^(@) - tan 20^(@) -2 tan 40^(@)=

(tan80^(@)-tan10^(@))/(tan70^(@))=k, then k=?

Prove that tan70^(@)-tan20^(@)=2tan50^(@) .

Assertion (A) : tan 70^(@) - tan 20^(@) = 2 cot 40^(@) Reason (R ) : If A + B = 90^(@) then tan A. tan B = 1

tan70^@-tan20^@-2tan40^@=