Question

Найти область значений функции

$y = 1 - cos^{2} frac{2 pi x}{3}$

Answer 1

y=1-cos²(2πx/3)
y=1-(1+cos(4πx/3))/2=1-1/2-1/2*cos(4πx/3)=1/2-1/2*cos(4πx/3)
E(y)=1/2-1/2*[-1;1]=1/2-[-1/2;1/2]=[0;1]