/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 34 Finding a Limit In Exercises \(1... [FREE SOLUTION] | 91Ó°ÊÓ

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Finding a Limit In Exercises \(19-38,\) find the limit. $$ \lim _{x \rightarrow-\infty} \frac{2 x}{\left(x^{6}-1\right)^{1 / 3}} $$

Short Answer

Expert verified
The limit of the given function as x approaches negative infinity is 0.

Step by step solution

01

Understanding the problem

The given function is given by \(\frac{2x}{{(x^6-1)}^{1/3}}\). We are supposed to find the limit of this function as \(x\) approaches negative infinity.
02

Analyze the behavior at infinity

As x approaches negative infinity, the term \((x^6-1)^{1 / 3}\) also tends to minus infinity. Since the numerator is directly proportional to \(x\), it also tends to minus infinity. So it is an indeterminate form of type \( \frac{-\infty}{-\infty}\). We can further simplify the expression to easier calculate the limit.
03

Simplification

Divide both the numerator and the denominator by \(x^2\). The function becomes \(\frac{2}{{(x^4-\frac{1}{x^2})}^{1/3}}\). Now, as \(x\) tends to negative infinity, the function simplifies to \(\frac{2}{-|x|}\).
04

Final computation

The limit of \(\frac{2}{-|x|}\) as \(x\) approaches negative infinity is \(0\).

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Indeterminate Forms
When dealing with limits, particularly involving infinity, you might encounter situations that seem undefined or nonsensical at first glance. These are known as indeterminate forms. An example is when both the numerator and the denominator in a fraction approach infinity, like \(\frac{-\infty}{-\infty}\). This indicates that simple substitution won't work, and we need to analyze further to find a clear answer.
  • Indeterminate forms can sometimes be reduced to a simpler form that we can evaluate.
  • This often involves algebraic manipulation, such as factoring or using conjugates.
  • By rewriting the expression, we can uncover the true behavior of the function as it approaches infinity.
Understanding indeterminate forms is critical. It highlights the need to look deeper and not take numerical forms as final results until simplified.
Infinity in Calculus
Infinity represents a concept in calculus, rather than an actual number. When dealing with functions approaching infinity, it's important to note how they behave rather than focusing on specific values. Seeing how a function behaves as it approaches infinity can solve complex limit problems.
  • Consider the direction of approach: Whether a function is approaching positive or negative infinity impacts its behavior.
  • When solving limits, you often assess how the degree of terms in a polynomial relate, which helps determine dominance as \(x\) approaches infinity.
  • Simplifying complex expressions often involves identifying dominant terms that dictate behavior at large values of \(x\).
In the exercise, we observed how both the numerator and denominator approach infinity, initially causing an indeterminate form. Our task was to resolve this to better understand the limit at negative infinity.
Simplification of Expressions
Simplification is essential in dealing with complex mathematical expressions or indeterminate forms. It's the bridge between complicated original forms and understandable results. In the given solution, simplification allowed us to move from the indeterminate form to a limit result of zero. To simplify expressions effectively:
  • Divide both the numerator and denominator by the highest power of \(x\) seen in the denominator.
  • Factor out common terms and reduce fractions where applicable.
  • In cases involving powers or roots, consider the dominant terms as \(x\) approaches infinity, simplifying fractional powers accordingly.
By following these steps, we were able to simplify the function to \(\frac{2}{-|x|}\), clarifying the limit calculation. This process showed how seemingly complex problems could be broken down into manageable steps. Simplification, therefore, not only provides clarity but also guides us towards the solution in an efficient manner.

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Most popular questions from this chapter

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