Question

Найдите множество значений функции y=2[sinx]-1.................sinx по модулю

Answer 1

$-1 leq sin(x) leq 1\\ 0 leq |sin(x)| leq 1\\ 2*0 leq 2*|sin(x)| leq 2*1\\ 0 leq 2*|sin(x)| leq 2\\ 0-1 leq 2*|sin(x)|-1 leq 2-1\\ -1 leq 2*|sin(x)|-1 leq 1\\ -1 leq y(x) leq 1\\ yin[-1; 1]$