Natural Log Inequality: True or Misunderstanding?

In summary, a natural log inequality is an inequality that contains a natural logarithm function, written as ln(x), which is the inverse of the exponential function. These inequalities are solved using the properties of logarithms and the rules of inequalities. To determine if a natural log inequality is true or false, one can use a graphing calculator or algebraic techniques. Multiple solutions can exist for a natural log inequality due to the one-to-one nature of the natural logarithm function. Common mistakes when solving these inequalities include forgetting to account for the domain of the natural log function and not applying the rules of inequalities correctly. Natural log inequalities have real-world applications in fields such as biology, economics, finance, physics, chemistry, and engineering.
  • #1
tmt1
234
0
I was talking to my professor and she said that $(ln n)^a < n$ for all values of $a$. Is this true or was I misunderstanding?
 
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  • #2
It's false. Consider $\ln^3\left(e^2\right)$ and note that $e^2\approx7.4$.
 
  • #3
greg1313 said:
It's false. Consider $\ln^3\left(e^2\right)$ and note that $e^2\approx7.4$.

I forgot an important detail. This is in context of $n$ approaching infinity.
 
  • #4
You 'forgot' that? You completely denied it when you said "for all n"!
 
  • #5
This is essentially a question of limits - moved to Pre-Calculus.

tmt, do you think it's true? False? Explain your reasoning.
 

1. What is a natural log inequality?

A natural log inequality is an inequality that contains a natural logarithm function. This function is written as ln(x) and is the inverse of the exponential function, e^x. Inequalities with natural logs are solved using the properties of logarithms and the rules of inequalities.

2. How do you know if a natural log inequality is true or false?

To determine if a natural log inequality is true or false, you can use a graphing calculator or graphing software to plot the inequality and see where the solution lies. You can also use algebraic techniques, such as isolating the variable and testing a few values to see if they satisfy the inequality.

3. Can a natural log inequality have multiple solutions?

Yes, a natural log inequality can have multiple solutions. This is because the natural logarithm function is a one-to-one function, meaning that each input has a unique output. Therefore, if there are multiple values of x that satisfy the inequality, they will all be valid solutions.

4. What are the common mistakes made when solving natural log inequalities?

One common mistake is forgetting to account for the domain of the natural logarithm function. The natural log function is only defined for positive values, so any solutions that result in a negative input for the natural log will be extraneous and must be discarded. Another mistake is not applying the rules of inequalities correctly, such as reversing the inequality symbol when multiplying or dividing by a negative number.

5. Are there any real-world applications of natural log inequalities?

Yes, natural log inequalities are used in various fields of science and economics. For example, in biology, natural log inequalities can be used to model population growth and decay. In finance, they can be used to calculate compound interest rates. They also have applications in physics, chemistry, and engineering for modeling exponential decay and growth processes.

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