CBSE Class 12 Applied Mathematics — Calculus (Application of Derivatives / Integrals)

(a) Find the intervals in $\mathbb{R}$ for which the function $f(x) = x^4 - 2x^2$ is increasing or decreasing. OR (b) Find : $\int \frac{2x + 1}{\sqrt{18 - 4x - x^2}} dx$