[tex]\boxed{\begin{array}{l}\sf tg(\alpha)=\dfrac{sen(\alpha)}{cos(\alpha)} \\\sf tg(\alpha)=\dfrac{\frac{3}{\diagdown\!\!\!5}}{-\frac{4}{\diagdown\!\!\!5}}\\\sf tg(\alpha)=-\dfrac{3}{4}\\\huge\boxed{\boxed{\boxed{\boxed{\sf\maltese~alternativa~b}}}}\end{array}}[/tex]
