Skip to main content
Ch. 2 - Limits
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243Non è quello che usi tu?Cambia libro di testo
Capitolo 2, Problema 27

Determine the following limits.
lim x→5 x − 7 / x(x − 5)^2

Guida verificata passo dopo passo
1
Identify the type of limit problem: This is a limit as \( x \) approaches 5, and the expression is \( \frac{x - 7}{x(x - 5)^2} \).
Check for direct substitution: Substitute \( x = 5 \) into the expression to see if it results in an indeterminate form. \( \frac{5 - 7}{5(5 - 5)^2} = \frac{-2}{0} \), which is undefined.
Recognize the indeterminate form: Since the denominator becomes zero, this is a case of an indeterminate form, suggesting the need for further analysis.
Consider simplifying or factoring: Since direct substitution leads to an undefined form, consider simplifying the expression or using algebraic manipulation to resolve the indeterminate form.
Apply L'Hôpital's Rule if applicable: If the limit results in \( \frac{0}{0} \) or \( \frac{\infty}{\infty} \), L'Hôpital's Rule can be used by differentiating the numerator and the denominator separately and then taking the limit again.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
2m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Limits

A limit is a fundamental concept in calculus that describes the behavior of a function as its input approaches a certain value. It helps in understanding how functions behave near points of interest, including points where they may not be defined. In this case, we are interested in the limit as x approaches 5, which requires evaluating the function's behavior close to that point.
Video consigliato:
05:50
One-Sided Limits

Indeterminate Forms

Indeterminate forms occur in limit problems when direct substitution leads to expressions like 0/0 or ∞/∞. These forms require further analysis, often using algebraic manipulation, L'Hôpital's Rule, or other techniques to resolve the limit. In the given limit, substituting x = 5 results in an indeterminate form, necessitating additional steps to find the limit.
Video consigliato:
3:56
Slope-Intercept Form

L'Hôpital's Rule

L'Hôpital's Rule is a method used to evaluate limits that result in indeterminate forms, specifically 0/0 or ∞/∞. It states that if the limit of f(x)/g(x) leads to an indeterminate form, the limit can be found by taking the derivative of the numerator and the derivative of the denominator separately. This rule can simplify the process of finding limits, especially when direct evaluation is complex.
Video consigliato:
5:50
Power Rules