Math Problem Statement
ln(x-3) + ln(2x+3) = ln(-4x^2)
Solution
The given equation is:
Step 1: Combine the logarithmic terms on the left-hand side
Using the logarithmic property , we rewrite the left-hand side:
Step 2: Equating the arguments of the logarithms
Since the natural logarithmic function is one-to-one, we can equate the arguments:
Step 3: Expand the left-hand side
Expand the product on the left:
Simplify:
Step 4: Combine like terms
Bring all terms to one side of the equation:
Step 5: Simplify the equation
Factor out a 3:
Step 6: Solve the quadratic equation
Focus on solving . Use the quadratic formula:
Here, , , and . Substitute into the formula:
Step 7: Compute the roots
Step 8: Check for extraneous solutions
The arguments of the logarithmic functions must be positive. Substituting into the original equation:
which is invalid since logarithms of negative numbers are undefined. Therefore, is not a solution.
Substituting :
is also invalid. Hence, no solution satisfies the equation.
Final Answer:
The equation has no solution.
Would you like further clarification or details? Here are some related questions:
- What are the rules for solving logarithmic equations?
- Why can't logarithms of negative numbers be calculated in real numbers?
- Can this equation have solutions in the complex domain?
- What are some examples of logarithmic equations with valid solutions?
- How do the properties of logarithms simplify solving equations?
Tip: Always check for restrictions (domain) when solving logarithmic equations to avoid extraneous solutions.
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Math Problem Analysis
Mathematical Concepts
Logarithmic Equations
Properties of Logarithms
Quadratic Equations
Domain Restrictions
Formulas
Logarithmic property: ln(a) + ln(b) = ln(a * b)
Quadratic formula: x = (-b ± √(b² - 4ac)) / (2a)
Theorems
One-to-one property of logarithmic functions: ln(a) = ln(b) implies a = b
Suitable Grade Level
Grades 10-12