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 43

Find the following limits or state that they do not exist. Assume a, b , c, and k are fixed real numbers.


lim t→5 (1/t^2 − 4t − 5 −1/ 6(t − 5))

Guida verificata passo dopo passo
1
Identify the limit expression: \( \lim_{{t \to 5}} \left( \frac{1}{t^2 - 4t - 5} - \frac{1}{6(t - 5)} \right) \).
Factor the quadratic expression in the denominator: \( t^2 - 4t - 5 = (t - 5)(t + 1) \).
Rewrite the limit expression using the factored form: \( \lim_{{t \to 5}} \left( \frac{1}{(t - 5)(t + 1)} - \frac{1}{6(t - 5)} \right) \).
Combine the fractions over a common denominator: \( \frac{1}{(t - 5)(t + 1)} - \frac{1}{6(t - 5)} = \frac{6 - (t + 1)}{6(t - 5)(t + 1)} \).
Simplify the numerator: \( 6 - (t + 1) = 5 - t \), and then evaluate the limit as \( t \to 5 \).

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:
5m

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 question, we are tasked with finding the limit of a function as t 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 calculus when direct substitution into a limit results in expressions like 0/0 or ∞/∞. These forms require further analysis, often using algebraic manipulation or L'Hôpital's Rule, to resolve the limit. In the given question, substituting t = 5 directly into the expression leads to 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 of indeterminate forms by differentiating the numerator and denominator. If a limit results in 0/0 or ∞/∞, applying this rule can simplify the expression and help find the limit. In this case, if the limit leads to an indeterminate form, L'Hôpital's Rule may be a suitable approach to determine the limit as t approaches 5.
Video consigliato:
5:50
Power Rules