
1. log1/3 (2x) >-22. log0.5(x^2+1) меньше или равно log0.5(2x-5)


Ответы на вопрос

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1.
Iog_(1/3) (2x) > -2 * * * ОДЗ : x >0 * * *
т.к. основание логарифма 0 < 1/3 < 1 ,то
0 < 2x < (1/3)⁻² ⇔ 0< 2x < 9 ⇔ 0 < x <4,5 .
ответ: x ∈( 0 ; 4,5) .
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2.
log_(0,5) (x²+ 1) ≤ log_(0,5) (2x -5) ; ОДЗ : 2x -5 >0 ⇔ x > 2,5 .
основание логарифма (0,5) меньше единицы ,следовательно
x²+ 1 ≥ 2x -5 > 0 ;
x² -2x +6 ≥ 0 D₁=1² -6 = -5 < 0 * * * или D=2² -4*1*6 = -20 < 0 * * *
(x -1)² +5 ≥ 0 ⇒ x ∈( -∞ ; ∞)_для всех x * * * x ∈R * * *
учитывая ОДЗ пишем
ответ: x ∈( 2,5 ; ∞) .



To solve the inequality log₁/₃(2x) > -22 and log₀.₅(x²+1) ≤ log₀.₅(2x-5), we need to use some logarithmic properties to simplify and isolate the variable x.
log₁/₃(2x) > -22: Using the property that logₐ(b) > c is equivalent to a^c < b, we can rewrite the first inequality as follows: 1/3^(22) < 2x (1/3)^(22) < 2x (1/3)^22 < 2x
log₀.₅(x²+1) ≤ log₀.₅(2x-5): Since both sides have the same base (0.5), we can remove the logarithms and compare the expressions inside the logarithms directly: x² + 1 ≤ 2x - 5
Now we have two inequalities:
- (1/3)^22 < 2x
- x² + 1 ≤ 2x - 5
Let's solve each inequality separately:
- (1/3)^22 < 2x: Calculate (1/3)^22 ≈ 1.66533454 x 10^(-13) (a very small positive value) 1.66533454 x 10^(-13) < 2x
Since 1.66533454 x 10^(-13) is essentially zero compared to 2x, we can consider it negligible. So the first inequality is effectively 0 < 2x.
- x² + 1 ≤ 2x - 5: Move all terms to one side of the inequality: x² - 2x + 6 ≤ 0
Now, we need to find the values of x that satisfy this inequality. You can use various methods, such as factoring or the quadratic formula, to solve this quadratic inequality.
By factoring: (x - 3)(x + 2) ≤ 0
Now we have three intervals to test: x < -2, -2 ≤ x ≤ 3, and x > 3.
Testing the intervals:
For x < -2: Let's take x = -3 (a value less than -2) (-3 - 3)(-3 + 2) ≤ 0 (-6)(-1) ≤ 0 6 ≤ 0 (false)
For -2 ≤ x ≤ 3: Let's take x = 0 (a value between -2 and 3) (0 - 3)(0 + 2) ≤ 0 (-3)(2) ≤ 0 -6 ≤ 0 (true)
For x > 3: Let's take x = 4 (a value greater than 3) (4 - 3)(4 + 2) ≤ 0 (1)(6) ≤ 0 6 ≤ 0 (false)
So, the values of x that satisfy the inequality x² + 1 ≤ 2x - 5 are -2 ≤ x ≤ 3.
Now, we need to find the intersection between the solutions of both inequalities:
From the first inequality, we found that 0 < 2x. From the second inequality, we found that -2 ≤ x ≤ 3.
The common range is 0 < 2x ≤ 3.
Divide by 2 to get 0 < x ≤ 3/2.
The final solution for the inequality system is 0 < x ≤ 3/2.


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