1. ## Integrate

Integrate the following with respect to x

3 x squared

and,

cos 2 x

2. $\displaystyle \begin{gathered} \int {kx^n } = k\int {x^n } = k\frac{{x^{n + 1} }} {{n + 1}} + C \hfill \\ \int {\cos (kx) = \sin (kx)/k + C} \hfill \\ \end{gathered}$