Ребят, помогите пожалуйста, голову целый день ломал:(

1)8cosπ/33*cos2π/33*cos4π/33*cos8π/33*cos16π/33=(умножим делим sinπ/33)=(8*cosπ/33*sinπ/33):(sinπ/33)*(cos2π/33*cos4π/33)*cos8π/33*cos16π/33==4/(sinπ/33)*sin2π/33*cos2π/33*cos4π/33*cos8π/33*cos16π/33=2/(sinπ/33)*sin4π/33*cos4π/33*cos8π/33*cos16π/33=1/(sin2π/33)*sin8π/33*cos8π/33*cos16π/33=1/(sinπ/33)*1/2*sin16π/33*cos16π/331/(sinπ/33)*1/2*1/2sin32π/33=1/(sinπ/33)*1/4*sin(π-32π/33)=1/(sinπ/33)*1/4*sinπ/33=1/4