Applying the trigonometric identity: $1+\tan\left(\theta \right)^2 = \sec\left(\theta \right)^2$

Applicare l'identità trigonometrica: $\sec\left(\theta \right)^n$$=\frac{1}{\cos\left(\theta \right)^n}$, dove $n=2$

Applicare la formula: $\frac{a}{\frac{b}{c}}$$=\frac{ac}{b}$, dove $a=\left(1+\tan\left(x\right)\right)\left(1-\tan\left(x\right)\right)$, $b=1$, $c=\cos\left(x\right)^2$, $a/b/c=\frac{\left(1+\tan\left(x\right)\right)\left(1-\tan\left(x\right)\right)}{\frac{1}{\cos\left(x\right)^2}}$ e $b/c=\frac{1}{\cos\left(x\right)^2}$