Question

1)sin2π/3=. 2)Cos 2π/3. 3) tg2π/3. 4)ctg2π/3.

Answer 1

1)sin(120°) = ½√3 2)cos(120°) = -1/2 3)tg(120°) = -√3 4)ctg(120°) = -1/√3

Answer 2

$sinfrac{2pi }{3}=sin(pi -frac{pi}{3})=sinfrac{pi}{3}=frac{sqrt3}{2}\\cosfrac{2pi}{3}=cos(pi-frac{pi}{3})=-cosfrac{pi}{3}=-frac{1}{2}\\tgfrac[2pi}{3}=tg(pi -frac{pi}{3})=-tgfrac{pi}{3}=-sqrt3\\ctgfrac{2pi}{3}=ctg(pi -frac{pi}{3})=-ctgfrac{pi}{3}=-frac{sqrt3}{3}$