Find the value of \[ \int \frac{\sec^2 2x}{(\cot x - \tan x)^2} \, dx. \]
Solve:
If
\[ A = \begin{bmatrix} 1 & -1 & 0 \\ 2 & 3 & -2 \\ -2 & 0 & 1 \end{bmatrix}, \quad B = \begin{bmatrix} 3 & -15 & 5 \\ -1 & 6 & -2 \\ 1 & -5 & 2 \end{bmatrix}, \]
then find the value of \( (AB)^{-1} \).
Prove that \[ \int_0^{\pi} \frac{x \tan x}{\sec x + \tan x} \, dx = \frac{\pi}{2} (\pi - 2). \]
Find the value of \[ \int e^x \left( \tan^{-1} x + \frac{1}{1 + x^2} \right) dx. \]
Integrate \[ \int \frac{\sin(\tan^{-1} x)}{1 + x^2} \, dx. \]