cos^2x+sinxcosx=1
sinx*cosx=1-cos^2x
sinxcosx=sin^2x
sin^2x-sinx*cosx=sinx(sinx-cosx)=0
sinx=0 x=Пk
x1=0; х2=-П
sinx=cosx
tgx=1
x=п/4+Пk
x3=П/4
x3=-П/4
x4=-3П/4
x5=-7П/4
S=П/4-П/4-3П/4-7П/4-П=-3,5П
cos^2x+sinxcosx=1
sinx*cosx=1-cos^2x
sinxcosx=sin^2x
sin^2x-sinx*cosx=sinx(sinx-cosx)=0
sinx=0 x=Пk
x1=0; х2=-П
sinx=cosx
tgx=1
x=п/4+Пk
x3=П/4
x3=-П/4
x4=-3П/4
x5=-7П/4
S=П/4-П/4-3П/4-7П/4-П=-3,5П