Show that :
(i) ` tan\ 48^@ tan 23^@\ tan 42^@tan 67^@=1`
(ii) `cos 38^@\ cos 52^@ - sin 38^@ sin 52^@=0`

Explanation

To solve the given problems, we will tackle each part step-by-step.

### Part (i): Show that \( \tan 48^\circ \tan 23^\circ \tan 42^\circ \tan 67^\circ = 1 \)

**Step 1:** Write down the left-hand side (LHS) of the equation.
\[ \text{LHS} = \tan 48^\circ \tan 23^\circ \tan 42^\circ \tan 67^\circ \]
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