Applicare la formula: $\int xdx$$=\frac{1}{2}x^2+C$, dove $x=\theta$

Applicare la formula: $\left[x\right]_{a}^{b}$$=eval\left(x,b\right)-eval\left(x,a\right)+C$, dove $a=3\pi $, $b=6\pi $ e $x=\frac{1}{2}\theta^2$

Applicare la formula: $\frac{a}{b}c$$=\frac{ca}{b}$, dove $a=1$, $b=2$, $c=-1$, $a/b=\frac{1}{2}$ e $ca/b=- \left(\frac{1}{2}\right)\cdot \left(3\pi \right)^2$