" (ii) "tan15^(@)*tan30^(@)*tan45^(@)*tan60^(@)*tan75^(@)=1

Find the value of the following: tan15^(@)tan30^(@)tan45^(@)tan60^(@)tan75^(@)

Find tan15^(@).tan25^(@).tan45^(@).tan65^(@).tan75^(@) .

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

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

tan30^(@)*sec45^(@)+tan60^(@)*sec30^(@)

tan 10^(@)*tan20^(@)*tan30^(@)*tan40^(@)*tan50^(@)*tan60^@tan70^(@)*tan80^(@)=

tan15^(@) + tan 75^(@)=

Show that (i) cos60^(@)*cos30^(@)-sin60^(@)*sin30^(@)=cos90^(@) (ii) cos60^(@)=1-2sin^(2)30^(@)=2cos^(2)30^(@)-1 (iii) (tan60^(@)-tan30^(@))/(1+tan60^(@)*tan30^(@))=tan30^(@)

tan10^(@) tan 20^(@) tan 30^(@) tan 40^(@) tan 50^(@) tan 60^(@) tan 70^(@) tan 80^(@)=