`cot 6^0 cot 42^0 cot 66^0 cot 78^0=1`

cot6^(0)cot42^(0)cot66^(@)cot78^(@)=1

cot16^(0)cot44^(0)+cot44^(0)cot76^(0)-cot76^(0)cot16^(0)=(a)1(b)2(c)3(d)4

cot B cot C+cot C cot A+cot A cot B=1

Without using trigonometric tables, evaluate the following: (sec37^0)/(cos e c53^0)+2cot15^0cot25^0cot45^0cot75^0cot65^0(sin^2 18^0+sin^2 72^0)

What is cot 2x cot 4x -cot4x cot 6x- cot6x cot 2x equal to ?

If A=tan6^(@) tan 42^(@) and B= cot 66^(@)cot 78^(@) then-

The value of (cot84^(@)cot48^(@))/(cot66^(@)cot78^(@)) is equal to