Question

2cos(pi*x-pi)=корень из 2

Answer 1

$2cos( pi x- pi )= sqrt{2} \ cos( pi x- pi )= frac{sqrt{2}}{2} \ pi x- pi =pm frac{ pi }{4}+ 2 pi k, k in Z \ pi x=pm frac{5 pi }{4}+2 pi k, k in Z (: pi ) \ x=pm frac{5}{4}+2k,k in Z$