i.3.1.52 Indefinite integrals

Condition: Find the indefinite integrals: a) \( \int \frac{2 d x}{(x-1)(x-2)(x-3)} \), b) \( \int \frac{\cos 2 x d x}{1+\cos 2 x} \) c) \( \int \frac{\sqrt[4]{x}+1}{\sqrt[4]{x^{3}}(\sqrt{x}+4)} d x \)