Limit Calc: Find $\lim\limits_{t\to -1} \frac{\sqrt[3]{t}+1}{\sqrt[5]{t}+1}

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SUMMARY

The limit calculation for the expression \(\lim\limits_{t\to -1} \frac{\sqrt[3]{t}+1}{\sqrt[5]{t}+1}\) can be approached without using L'Hôpital's rule. To solve this limit, one should utilize the identities for the sum of cubes and the sum of fifth powers. Specifically, multiplying the numerator and denominator by suitable forms of 1 will simplify the expression and allow for the limit to be evaluated directly.

PREREQUISITES
  • Understanding of limits in calculus
  • Familiarity with radical expressions
  • Knowledge of algebraic identities for sums of cubes and fifth powers
  • Basic skills in manipulating fractions
NEXT STEPS
  • Study the algebraic identity for the sum of cubes: \((a + b)(a^2 - ab + b^2) = a^3 + b^3\)
  • Explore the algebraic identity for the sum of fifth powers: \((a + b)(a^4 - a^3b + a^2b^2 - ab^3 + b^4) = a^5 + b^5\)
  • Practice evaluating limits without L'Hôpital's rule using algebraic manipulation
  • Review techniques for simplifying expressions involving radicals
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Students in calculus, particularly those studying limits and algebraic manipulation, as well as educators looking for teaching strategies in limit evaluation without L'Hôpital's rule.

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Homework Statement


Find the limit \lim\limits_{t\to -1}\frac{\sqrt[3]{t}+1}{\sqrt[5]{t}+1}. Needless to say: No L'Hopital's rule, otherwise this thread would not exist.

Homework Equations

The Attempt at a Solution


Have tried multiplying the fraction such that I get the difference of squares in denominator - no avail.
This is analysis 1 course material .. *blushes*

There is something I have forgotten about, this is supposed to be a really easy problem.
Hints, anyone?
 
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nuuskur said:

Homework Statement


Find the limit \lim\limits_{t\to -1}\frac{\sqrt[3]{t}+1}{\sqrt[5]{t}+1}. Needless to say: No L'Hopital's rule, otherwise this thread would not exist.

Homework Equations

The Attempt at a Solution


Have tried multiplying the fraction such that I get the difference of squares in denominator - no avail.
This is analysis 1 course material .. *blushes*

There is something I have forgotten about, this is supposed to be a really easy problem.
Hints, anyone?

Did somebody forbid you from using l'Hospital's rule?
 
nuuskur said:
Have tried multiplying the fraction such that I get the difference of squares in denominator - no avail.
Of course that won't work -- neither radical contains a square root.

What will work is to multiply each of the numerator and denominator by 1, in a suitable form.

Hint 1: ##(a + b)(a^2 - ab + b^2) = a^3 + b^3##
Hint 2: ##(a + b)(a^4 -a^3b + a^2b^2 - ab^3 + b^4) = a^5 + b^5##
 
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