Модуль cosx-0.5 модуль закрывается -sinx=0.5

COSx>1/2  cosx-0,5-sinx=1/2 cosx-sinx=1                                              1-2sinxcosx=1                                              sin2x=0                                             x=пk/2 -п/3+2Пk<=x<=П/3+2пk x=2Пk cosx<1/2 0,5-cosx-sinx=1/2                    cosx=-sinx                   tgx=-1 x=-п/4+пk П/3+2Пk