Shown that : `tan48^(@)tan23^(@)tan42^(@)tan67^(@)=1`

Explanation

To prove that \( \tan 48^\circ \tan 23^\circ \tan 42^\circ \tan 67^\circ = 1 \), we can use the properties of complementary angles in trigonometry.

### Step-by-Step Solution:

1. **Identify Complementary Angles**:
We know that two angles are complementary if their sum is \( 90^\circ \). Therefore, we can express some of the angles in terms of their complementary angles:
\[
\tan(90^\circ - \theta) = \cot(\theta)
...