-
The simplest value of cot 9° cot 27° cot 63° cot 81° is
-
- 0
- 1
- - 1
- √3
Correct Option: B
Expression
= cot 9°. cot 27°. cot 63° . cot 81°
= cot 9°. cot 27°. cot (90° – 27°) . cot (90° – 9°)
= cot 9° . cot 27° . tan 27° . tan 9° [tan (90° – θ)
= cot θ; cot (90° – θ) = tan θ ]
= cot 9° . tan 9° . cot 27° tan 27°
= 1 [tan θ . cot θ = 1]
