Desenvolvi desta maneira:
[tex3]sen^3\ x.cos\ x-3.sen\ x.cos^3\ x=0\\cos\ x(sen^3\ x-3.sen\ x.cos^2\ x)=0\\cos\ x=0\ ou\ sen^3\ x-3.sen\ x.cos^2\ x=0\\sen^3\ x-3.sen\ x.(1-sen^2\ x)=0\\4.sen^3\ x-3.sen\ x=0\\sen\ x(4.sen^2\ x-3)=0\\sen\ x=0\ ou\ 4.sen^2\ x-3=0\\sen^2\ x=\frac{3}{4}\rightarrow sen\ x=\pm \frac{\sqrt{3}}{2}\\cos\ x=0\rightarrow \frac{\pi }{2},\frac{3\pi }{2}\\sen\ x=0\rightarrow \pi ,2\pi \\sen\ x=\frac{\sqrt{3}}{2}=\frac{\pi }{3},\frac{2\pi}{3},\frac{4\pi }{3}\frac{5\pi }{3}[/tex3]
Onde estou errando?
Resposta
[tex3]S=(0,\frac{\pi }{3},\frac{\pi }{2},\frac{2\pi }{3},\pi ,\frac{4\pi }{3},\frac{3\pi }{2},\frac{5\pi }{3})[/tex3]
