Question

Se sen x = tg x, quanto vale cos x? x = {0;2π}

Answer 1

$sen(x)=tg(x)\\ \\ sen(x)=\frac{sen(x)}{cos(x)}\\ \\ 1=\frac{1}{cos9x)}\\ \\ cos(x)=1\\ \\ x=0 \ \ ou \ \ x=2\pi \ rad$