Applicare la formula: $\frac{\frac{a}{b}}{\frac{c}{f}}$$=\frac{af}{bc}$, dove $a=1$, $b=\cos\left(x\right)$, $a/b/c/f=\frac{\frac{1}{\cos\left(x\right)}}{\frac{1}{\cos\left(x\right)\sin\left(x\right)}}$, $c=1$, $a/b=\frac{1}{\cos\left(x\right)}$, $f=\cos\left(x\right)\sin\left(x\right)$ e $c/f=\frac{1}{\cos\left(x\right)\sin\left(x\right)}$

Applicare la formula: $\frac{a}{a}$$=1$, dove $a=\cos\left(x\right)$ e $a/a=\frac{\cos\left(x\right)\sin\left(x\right)}{1\cos\left(x\right)}$