Evaluate : (i) `intsin3xsin2xdx` (ii) `intcos3xsin2xdx`
(iii) `intcos4xcosxdx` (iv) `intsin^(3)xcos^(3)xdx`

Explanation

Let's evaluate the given integrals step by step.

### (i) Evaluate \(\int \sin 3x \sin 2x \, dx\)

We can use the product-to-sum identities for sine functions:
\[ \sin A \sin B = \frac{1}{2} [\cos(A - B) - \cos(A + B)] \]
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