Applicare la formula: $\int\frac{n}{a}dx$$=n\int\frac{1}{a}dx$, dove $a=\sqrt{r^2-x^2}$ e $n=r$

Applicare la formula: $\int\frac{n}{\sqrt{a-b^2}}dx$$=n\arcsin\left(\frac{b}{\sqrt{a}}\right)+C$, dove $a=r^2$, $b=x$ e $n=1$

Applicare la formula: $\left(x^a\right)^b$$=x$, dove $a=2$, $b=1$, $x^a^b=\sqrt{r^2}$, $x=r$ e $x^a=r^2$

Applicare la formula: $\left[x\right]_{a}^{b}$$=eval\left(x,b\right)-eval\left(x,a\right)+C$, dove $a=0$, $b=r$ e $x=r\arcsin\left(\frac{x}{r}\right)$