A b числа
(а+b)/2=7.5
√ab=7.5*0.8=6
a+b=15
ab=36
a=15-b
b(15-b)=36
b²-15b+36=0
D=225-144=81
b1=(15+9)/2=12 тогда а1=3
b2=(15-9)/2=3 тогда а2=12
числа 3 и 12
Подставим корень в уравнение: 4^2+p*4+8=0
4p=-24
p=-6
Да тут легко!
28,6*2-240*2= - 2114/5= - 422,8
2Sin(2x + π/6) + 1 = √3Sin2x + Cosx
2(Sin2xCosπ/6 + Cos2xSinπ/6) + 1 = √3Sin2x + Cosx
2(Sin2x * √3/2 + Cos2x * 1/2) + 1 = √3Sin2x + Cosx
√3Sin2x + Cos2x + 1 = √3Sin2x + Cosx
Cos2x - Cosx + 1 = 0
2Cos²x - 1 - Cosx + 1 = 0
2Cos²x - Cosx = 0
Cosx(2Cosx - 1) = 0
1) Cosx = 0
x = π/2 + πn , n ∈ Z
2) 2Cosx - 1 = 0
2Cosx = 1
Cosx = 1/2
x= ± arcCos1/2 + 2πn , n ∈ Z
x = ± π/3 + 2πn , n ∈ Z