10 Cos² x + 3 Cos x -1 = 0
t = Cos x, |t| ≤ 1
10t² +3t -1 = 0
D = 9 +40 = 49
t = (-3 -7)/20 = -1/2
t = (-3+7)/20 = 1/5
Cos x = -1/2
x = ± 2π/3 +2πn, n ∈ Z
Cos x = 1/5
x = ± arccos(1/5) +2πn, n ∈ Z
А)(2а-1)2=2а2-1*2=4а2
б)(2х2+2х2)2=(4х+4х)2=8х+8х
Y = x*e^(x^2)
y'= (x*e^x^2)' = (x)' * e^x^2 + x * (e^x^2)' = e^x^2 + x * e^x^2 * (x^2)' = (1 + 2x^2)e^x^2
y'(-1) = (1 + 2) * e^1 = 3e
20х0,7+4х0,7(4х1,4-5х1,4):1,4=
1)4х1,4=5,6
2)5х1,4=7
3)5,6-7=-1,4
4)20х0,7=14
5)4х0,7=2,8
6)14+2,8=16,8
7)16,8х(-1,4)=-23,52