If `theta=pi/(2^n+1)` , prove that: `2^ncosthetacos2thetacos2^2 cos2^(n-1)theta=1.`

Explanation

To prove that \( 2^n \cos \theta \cos 2\theta \cos 2^2 \theta \cdots \cos 2^{n-1} \theta = 1 \) given \( \theta = \frac{\pi}{2^n + 1} \), we will follow these steps:

### Step 1: Rewrite the expression
We start with the expression we want to prove:
\[ 2^n \cos \theta \cos 2\theta \cos 2^2 \theta \cdots \cos 2^{n-1} \theta \]

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