Question

cot 12 cot 38 cot 52 cot 60 cot 78 is equals to 1 by root 3

Answer 1

Here's the solution.
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Answer 2

Answer

Cot 12° cot 38° cot 52° cot 60° cot 78°

Cot(90-78)× cot(90-52)× cot 52° ×

cot 60° × cot 78°

tan 78° × tan 52° × cot 52° × cot 60° ×

cot 78° 【cot(90-A)= tan A】

tan 78° × tan 52 ° × 1/tan52° × cot 60×

1/tan78° 【cot A= 1/tan A】

1 × 1 × cot 60° 【cot 60° = 1/√3】

1 × 1 × 1/√3 = 1/√3

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