Prove that:
`sin6^(@)sin42^(@)sin66^(@)sin78^(@)=1/16`

Explanation

To prove that \( \sin 6^\circ \sin 42^\circ \sin 66^\circ \sin 78^\circ = \frac{1}{16} \), we can use trigonometric identities. Let's break it down step by step.

### Step 1: Group the Sine Functions
We can group the sine functions in pairs:
\[ \sin 6^\circ \sin 66^\circ \quad \text{and} \quad \sin 42^\circ \sin 78^\circ \]

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