tenemos nuestra identidad
[tex]\frac{tan(x)+cos(x)}{sen(x)}=sec(x)+cot(x)\\ \frac{tan(x)}{sen(x)}+\frac{cos(x)}{sen(x)}=sec(x)+cot(x)\\ \\ \frac{\frac{sen(x)}{cos(x)}}{sen(x)}+\frac{cos(x)}{sen(x)}=sec(x)+cot(x)\\ \\ \frac{1}{cos(x)}+\frac{cos(x)}{sen(x)}=sec(x)+cot(x)[/tex]
sabemos que
[tex]\frac{1}{cos(x)}=sec(x)\\ \\ \frac{cos(x)}{sen(x)}=cot(x) [/tex]
asi que
[tex]\frac{1}{cos(x)}+\frac{cos(x)}{sen(x)}=sec(x)+cot(x)\\ \\ sec(x)+cot(x)=sec(x)+cot(x)[/tex]