Question

$cos frac{2 pi x}{3} = frac{ sqrt{3} }{2}$

Answer 1

$[tex]cosfrac{2pi}{3}x=frac{sqrt3}{2}\frac{2pi}{3}x=pm arccosfrac{sqrt3}{2}+2pi n\frac{2pi}{3}x=pm frac{pi}{6}+2pi n\x=pm frac{1}{3}+3 n, ; nin Z$