-9x^2=-2
x^2=2/9
x=√2/3
x=-√2/3
x1= -√2/3, x2= √2/3
| х-1 | = 9,5;
Х = 10,5;
Х = -8,5.
10,5 + (-8,5) = 2
Ответ: х = -8,5; 10,5.
A)sinπ/33*cosπ/33*cos2π/22*cos4π/33*cos8π/33*cos16π/33/sinπ/33=
=sin2π/33*cos2π/22*cos4π/33*cos8π/33*cos16π/33/(2sinπ/33)=
=sin4π/33*cos4π/33*cos8π/33*cos16π/33/(4sinπ/33)=
=sin8π/33*cos8π/33*cos16π/33/(8sinπ/33)=sin16π/33*cos16π/33/(16sinπ/33)=
=sin32π/33/(32sinπ/33)=sin(π-π/33)/32sinπ/33=(sinπ/33)/32sinπ/33=1/32
b)cosπ/7cos4π/7cos(π-2π/7)=-cosπ/7cos2π/7cos4π/7=
=(-sinπ/7cosπ/7cos2π/7cos4π/7)/(sinπ/7)=(-sin2π/7cos2π/7cos4π/7)/(2sinπ/7)=
=(-sin4π/7cos4π/7)/(4sinπ/7)=(-sin8π/7)/(8sinπ/7)=(-sinπ/7)/(8sinπ/7)=-1/8