Math Problem Statement
3 * log_5(x - 4) > 6/(log_5(x - 4) + 1)
Solution
Let's solve the inequality:
Step 1: Let
This substitution simplifies the inequality. Recall that is valid only when , so:
The inequality becomes:
Step 2: Eliminate the fraction
Multiply both sides by , assuming (to avoid division by zero):
Simplify:
Step 3: Solve the quadratic inequality
Divide through by 3:
Factorize the quadratic:
The critical points are and . Using a sign test, determine where the inequality is true:
- For , : false (both terms are negative).
- For , : false (one term is positive, the other is negative).
- For , : true (both terms are positive).
Thus, the solution for is:
Step 4: Back-substitute
We now solve:
Recall that implies . Therefore:
Step 5: Combine with initial condition
Initially, we had . Combining this with , the solution is:
Final Answer:
Let me know if you'd like a detailed explanation of any step or if you have more questions!
Related Questions:
- What are the properties of logarithmic inequalities?
- How do you perform a sign test for quadratic inequalities?
- How do you handle equations with multiple logarithms?
- Can logarithmic equations have extraneous solutions?
- How do transformations of logarithmic graphs affect inequality solutions?
Tip: Always check the domain of a logarithmic inequality before solving to ensure all expressions are valid!
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Math Problem Analysis
Mathematical Concepts
Logarithmic Inequalities
Quadratic Inequalities
Logarithmic Functions
Inequalities
Formulas
log_b(a) > c ==> a > b^c
ax^2 + bx + c = 0 (Quadratic Equation)
Sign Test for Quadratic Inequalities
Theorems
Logarithmic Properties
Quadratic Inequality Solutions
Suitable Grade Level
Grades 9-12