Find the following integrals.
\(\displaystyle \displaystyle\int \frac{x^2 - 3x - 1}{x^2 - 4x + 1} \, \mathrm{d}x \,,\)[3]
\(\displaystyle \displaystyle\int x \ln (kx) \, \mathrm{d}x \,,\) where \(k\) is a real constant,[2]
\(\displaystyle \displaystyle\int \frac{\sin \theta}{2 \cos 2\theta + 1} \, \mathrm{d}\theta \,,\) using the substitution \(x = \cos \theta\).[4]