Log3 (x+2) /=(больше или равно) 2 log1/3 (x-1)>/=-2 log2/3 (2-5x) < - 2

Лебедев Дмитрий Сергеевич

Учитель математики

Проверено учителем

To solve this system of inequalities, we must first establish the domain (ODZ) where all logarithmic functions are defined, and then solve the inequalities step-by-step. 1. Determining the Domain (ODZ) For a logarithm logb(a)log base b of a to exist, the argument aa must be strictly positive ( a>0a is greater than 0).

  1. x+2>0x>-2x plus 2 is greater than 0 ⟹ x is greater than negative 2 x1>0x>1x minus 1 is greater than 0 ⟹ x is greater than 1 25x>05x<2x<0.42 minus 5 x is greater than 0 ⟹ 5 x is less than 2 ⟹ x is less than 0.4

Intersection of conditions: The conditions x>1x is greater than 1 and x<0.4x is less than 0.4 are contradictory. There is no value of xx that is simultaneously greater than 1 and less than 0.4. 2. Analysis of the System The expression provided consists of several parts. Let's break them down to see if any part has a solution. Part A: log3(x+2)2log1/3(x1)log base 3 of open paren x plus 2 close paren is greater than or equal to 2 log base 1 / 3 of open paren x minus 1 close paren Using the base change formula log1/3(a)=log3(a)log base 1 / 3 of a equals negative log base 3 of a: log3(x+2)-2log3(x1)log base 3 of open paren x plus 2 close paren is greater than or equal to negative 2 log base 3 of open paren x minus 1 close paren log3(x+2)+log3(x1)20log base 3 of open paren x plus 2 close paren plus log base 3 of open paren x minus 1 close paren squared is greater than or equal to 0 log3((x+2)(x1)2)0log base 3 of open paren open paren x plus 2 close paren open paren x minus 1 close paren squared close paren is greater than or equal to 0This requires x>1x is greater than 1 from the argument (x1)open paren x minus 1 close paren. Part B: -2log2/3(25x)<-2negative 2 log base 2 / 3 of open paren 2 minus 5 x close paren is less than negative 2 Divide by -2negative 2 (and flip the inequality sign): log2/3(25x)>1log base 2 / 3 of open paren 2 minus 5 x close paren is greater than 1Since the base 2/32 / 3 is less than 1, we flip the inequality sign again when removing the log: 25x<(2/3)12 minus 5 x is less than open paren 2 / 3 close paren to the first power 22/3<5x2 minus 2 / 3 is less than 5 x 4/3<5xx>4/150.2664 / 3 is less than 5 x ⟹ x is greater than 4 / 15 is approximately equal to 0.266This requires x<0.4x is less than 0.4 from the argument (25x)open paren 2 minus 5 x close paren. 3. Conclusion To find the final solution, we must find the intersection of the requirements from all parts of the expression:

  • From the first part: x>1x is greater than 1 From the second part: x<0.4x is less than 0.4

Because the interval (1,+)open paren 1 comma positive infinity close paren and the interval (,0.4)open paren negative infinity comma 0.4 close paren do not overlap, there is no value of xx that satisfies the entire chain of inequalities. Final Answer: No solution (The set of solutions is empty: the empty set). Would you like me to double-check the signs or constants in the original equation to see if a small typo changed the outcome?

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