Respuesta :

caylus
Hello,

Let's assume 3t=a.

[tex] \dfrac{sin(a)+cos(a)}{cos(a)-sin(a)} = \dfrac{(cos(a)+sin(a))^2}{cos^2(a)-sin^2(a)}\\\\ = \dfrac{1+2sin(a)cos(a)}{cos(2a)}= \dfrac{1+sin(2a)}{cos(2a)} with\ a=3t[/tex]