Question

Срочноо!
cos (3x-pi/4) <= -1

Answer 1

$cos(3x- frac{ pi }{4} ) leq -1\ arccos(-1)+2 pi k leq 3x- frac{ pi }{4} leq 2 pi -arccos(-1)+2 pi k, k in Z\ pi +2 pi k leq 3x- frac{ pi }{4} leq 2 pi - pi +2 pi k, k in Z\ pi +2 pi k leq 3x- frac{ pi }{4} leq pi +2 pi k, k in Z\ pi +2 pi k+frac{ pi }{4} leq 3x leq pi +frac{ pi }{4}+2 pi k, k in Z\ frac{ 5pi }{4} +2 pi k leq 3x leq frac{ 5pi }{4} +2 pi k, k in Z$
$frac{ 5pi }{12} +frac{2 pi k }{3} leq x leq frac{ 5pi }{12} +frac{2 pi k }{3} , k in Z\ x=frac{ 5pi }{12} +frac{2 pi k }{3} , k in Z$