ДУГА АВС =110
угол аос = ДУГЕ НА КОТОРУЮ ОПИРАЕТСЯ Т. Е РАВЕН 110 ГРАДУСОВ
ОТВЕТ 110
47 центнеров будет 4т=40ц
700кг=7ц
3750-x+218=1230
3750-x=1012
x=3750-1012
x=2738
(cosx-sinx)+√2(cosx-sinx)(cosx+sinx)≥0
(cosx-sinx)*(1+√2cosx+√2sinx)≥0
(cosx-cos(π/2-x))*(1+2(√2/2*cosx+√2/2*sinx))≥0
-2sinπ/4*sin(x-π/4)*(1+2*sin(x+π/4))≥0
-√2*sin(x-π/4)*(1+2*sin(x+π/4))≥0
sin(x-π/4)*(1+2*sin(x+π/4))≤0
{sin(x-π/4)≤0⇒π+2πn≤x-π/4≤2π+2πn⇒5π/4+2πn≤x≤9π/4+2πn
{sin(x+π/4)≥-1/2⇒-π/6+2πn≤x+π/4≤7π/6+2πn⇒-5π/12≤x≤11π/12+2πn
или
{sin(x-π/4)≥0⇒2πn≤x-π/4≤π+2πn⇒π/4+2πn≤x≤5π/4+2πn
{sin(x+π/4)≤-1/2⇒7π/6+2πn≤x+π/4≤11π/6+2πn⇒11π/12≤x≤19π/12+2πn
x∈[-5π/12+2πn;π/4+2πn,n∈z] U 11π/12+2πn;5π/4+2πn,n∈z]