Integration - Integrable Forms of Trigonometric Functions

Integrate the following expressions with respect to \(x\).

1. \({\displaystyle\displaystyle\int 3\cos 7x + \sec^2 x \ \mathrm{d}x}\)
2. \({\displaystyle\displaystyle\int \frac{5}{x^4} - \cos(7x - 4) \ \mathrm{d}x}\)
3. \({\displaystyle\displaystyle\int \sin 5x - \sec^2 2x \ \mathrm{d}x}\)