[tex] \sin(30 =) = \frac{1}{2} \\ \cos(45) = \frac{1}{ \sqrt{2} } = \frac{ \sqrt{2} }{2} \\ \tan(60 ) = \frac{ \sqrt{3} }{1} [/tex]
resolvemos :
[tex] \frac{1}{2} \times \frac{ \sqrt{2} }{2} - \sqrt{3} = \frac{ \sqrt{2} }{4} - \sqrt{3} = - 1.38[/tex]
