Question

Cos ( 2pi / 3) + sen ( 3pi/2) + tg (5pi/4)

Answer 1

$Cos~( \frac{2 \pi }{3} )+ sen ( \frac{3 \pi }{2})+tg ( \frac{5 \pi }{4} ) \\ \\ Cos~120+ sen~ 270+ tg 225 \\ \\ -1/2+(-1)+1 \\ \\ -1/2-1+1 \\ \\ -1/2$