Express each of the following as a product: ` (i) sin4theta+sin2theta` (ii) `sin6theta-sin2theta` (iii) `cos4theta+cos8theta` (iv) `cos6theta-cos8theta`

Explanation

Let's solve the given expressions step by step.

### (i) Express `sin(4θ) + sin(2θ)` as a product:

1. **Identify the formula**: We use the formula for the sum of sines:
\[ \sin A + \sin B = 2 \sin\left(\frac{A + B}{2}\right) \cos\left(\frac{A - B}{2}\right) \]
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