Question

SOCORROOOO estou com muita dúvida

Answer 1

$3 \cdot cos( \frac{2 \pi }{3}) = 3\cdot (- \frac{1}{2}) = -\frac{3}{2} \\ \\ 2 \cdot sen( \frac{2 \pi }{3}) = 2\cdot(\frac{ \sqrt{3} }{2})= \sqrt{3} \\ \\ tg( \frac{4 \pi }{3})= \frac{sen( \frac{4 \pi }{3} )}{cos( \frac{4 \pi }{3} )}= \frac{ -\frac{ \sqrt{3} }{2} }{- \frac{1}{2} }= \sqrt{3} \\ \\ tg( \frac{2 \pi }{3} )= \frac{sen( \frac{2 \pi }{3} )}{cos( \frac{2 \pi }{3} )}= \frac{ \frac{ \sqrt{3} }{2} }{ -\frac{1}{2} }=- \sqrt{3}$
$2\cdot sen( \frac{4 \pi }{3} )=2\cdot(- \frac{ \sqrt{3} }{2} )=- \sqrt{3} \\ \\ cos( \frac{8 \pi }{3} ) = - \frac{1}{2} \\ \\ \\ y = \frac{ -\frac{3}{2}- \sqrt{3}+ \sqrt{3} }{- \sqrt{3}-(- \sqrt{3})- \frac{1}{2} } = \frac{- \frac{3}{2}- \sqrt{3}+ \sqrt{3} }{- \sqrt{3}+ \sqrt{3}- \frac{1}{2} } = \frac{ -\frac{3}{2} }{ -\frac{1}{2} }=3 \\ \\ y = 3$