f'=1/2+sinx/2=(1+sinx)/2
sinx=-1
x=-П/2+2Пk
f(x)=x/2-cosx/2
f'(x)=(x/2-cosx/2)=1/2+(1/2)*sinx
1/2+(1/2)*sinx=0
(1/2)(1+sinx)=0
x=-π/2+2πn, n є Z
f'=1/2+sinx/2=(1+sinx)/2
sinx=-1
x=-П/2+2Пk
f(x)=x/2-cosx/2
f'(x)=(x/2-cosx/2)=1/2+(1/2)*sinx
1/2+(1/2)*sinx=0
(1/2)(1+sinx)=0
sinx=-1
x=-π/2+2πn, n є Z