[tan20^(@)+2tan50^(@)=," (B) "cot70^(@)],[(C)sin70^(@)," (D) "tan30^(@)]

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

tan 40^(@) +2* tan 10^(@) = A) tan30^(@) B) tan50^(@) C) tan70^(@) D) tan90^(@)

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

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

tan10^(@)-tan50^(@)+tan70^(@)

If 2a=2tan10^(@)+tan50^(@), 2b=tan20^(@)+tan50^(@) 2c=2tan10^(@)+tan70^(@), 2d=tan20^(@)+tan70^(@) Then which of the following is/are correct ?

If 2a=2tan10^(@)+tan50^(@), 2b=tan20^(@)+tan50^(@) 2c=2tan10^(@)+tan70^(@), 2d=tan20^(@)+tan70^(@) Then which of the following is/are correct ?

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