Show that `tan48^(@) tan 23^(@) tan 42^(@) tan 67^(@) =1`.

Explanation

To show that \( \tan 48^\circ \tan 23^\circ \tan 42^\circ \tan 67^\circ = 1 \), we can use the properties of the tangent and cotangent functions.

### Step-by-Step Solution:

1. **Rewrite the expression**:
\[ \tan 48^\circ \tan 23^\circ \tan 42^\circ \tan 67^\circ \]
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