Prove that `tan 70^(@)=cot70^(@)++2cot40^(@)`

Prove that tan 70^(@)-tan 20^(@)-2 tan 40^(@)=4 tan 10^(@)

cot70^(@)+4cos70^(@)

Prove that tan 70^(@) - tan 20^(@) - 2 tan 40^(@) = 4 tan 10^(@) .

Prove that tan 315^(@) cot ( -405^(@) ) + cot 495^(@) tan (-585^(@)) = 2

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

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

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

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

Prove that: tan10^(@)tan50^(@)+tan50^(@)tan70^(@)+tan70^(@)tan170^(@)=3

Prove that cot70^@+4cos70^@=sqrt3