(i) ∫ cos2 (x/2) dx
\(\Rightarrow\) ∫ cos2 (\(\frac{x}{2}\)) dx
Now, we know that 1 + cos x = 2 cos2 (x/2)
So, applying this identity in the given integral, we get,
Now, we know that cosec2x - cot2x = 1
So, applying this identity in the given integral we get,
- 2 cot x - x + c