Find the value of `cos 12^(@)+cos 84^(@)+cos 156^(@)+cos 132^(@)`

Explanation

To find the value of \( \cos 12^\circ + \cos 84^\circ + \cos 156^\circ + \cos 132^\circ \), we can follow these steps:

### Step 1: Group the Cosine Terms
We can group the terms as follows:
\[ \cos 12^\circ + \cos 132^\circ + \cos 84^\circ + \cos 156^\circ \]

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