<span>x²-3x-10>0
D=9+40=49 </span>√D=7
x₁=(3+7)/2=5
x₂=(3-7)/2=-2
___+____-2____-______5______+_____
x∈(-∞;-2)∪(5;+∞)
..........................
<span>log4√2/2=1/2 log 2 2^-1/2=-1/4
</span><span>1,3 от 39= 1.3/39=0.033=3.33%</span>
<span>5sin3x - 9sin x = 0</span>
5(3sinx - 4sin^3 x) - 9sinx = 0
15sinx - 20sin^3 x - 9 sinx = 0
6sinx - 20sin^3 x = 0
2sinx (3 -10sin^2 x) = 0
a) 2sinx = 0
sinx = 0
x1= πn
б) 3 - 10sin^2 x = 0
10sin^2x = 3
sin^2x = 3/10
sinx = +-√(3/10)
sinx = √(3/10)
x2 = (-1)^n * arcsin(3/10)+πn
sinx = -√(3/10)
x3 = (-1)^(n+1) * arcsin(3/10)+πn
5x + 3/5 = x - 5/8
5x - x = - 3/5 - 5/8
4x = (-24 - 25)/40
x = -49/40 : 4
x = -49/160
Проверим: 5*(-49/160) + 3/5 = -49/160 - 5/8
-245/160 + 96/160 = -49/160 - 100/160
-149/160 = -149/160