sin11x=0 ; cos3x=0 ; sin3x=0
sin11x=0
11x=π*n
x1=πn/11
cos3x=0
3x=π/2+2πn
x2=π/6+2πn/3
sin3x=0
3x=πn
x3=πn/3
Ответ: πn/11 ; π/6+2πn/3 ; πn/3
N=S/2R...............n=S/2r
1/2cos2x=1/2(1-2sin^2x)=1/2-sin^2x
f'(x)=-2sinxcosx+cosx=cosx(1-2sinx)
cosx=0 x=П/2
sins=1/2 x=П/6
<span>y=1/2cos2x+sinx
y(0)=1/2
y(П/2)=1-1/2=1/2 min
y(П/6)=1/4+1/2=3/4 max</span>