Determining Limits: Simplifying Nasty Denominator

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SUMMARY

The limit as x approaches 0 for the function f(x) = [(1+x)^(1/2) - 1] / [(1+x)^(1/3) - 1] can be determined without using L'Hopital's Rule. The solution involves multiplying by the conjugate of the numerator, which leads to a complex denominator. A more effective approach is to utilize the sum of cubes technique, which simplifies the expression significantly. The discussion concludes with the realization that Taylor series can also be applied to find the limit.

PREREQUISITES
  • Understanding of limits and continuity in calculus
  • Familiarity with Taylor series expansion
  • Knowledge of algebraic manipulation techniques, including conjugates
  • Basic concepts of cube roots and their properties
NEXT STEPS
  • Study the application of Taylor series for functions near a point
  • Learn about the sum of cubes factorization and its uses
  • Explore advanced limit techniques without L'Hopital's Rule
  • Practice problems involving limits with complex denominators
USEFUL FOR

Students studying calculus, particularly those focusing on limits and algebraic manipulation, as well as educators looking for teaching strategies for limit problems without L'Hopital's Rule.

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Homework Statement


Determine the limit as x approaches 0 of

f(x) = [(1+x)1/2 - 1] / [(1+x)1/3 - 1]


Homework Equations


I am not allowed to use L'Hopital's Rule.


The Attempt at a Solution


I multiplied by the conjugate of the numerator and got a nasty denominator that I cannot simplify nicely. Can someone give me a lead?
 
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May you use taylor series?
 
mathmadx said:
May you use taylor series?

I just found out that I should multiply by an expression to get a sum of cubes (totally forgot about that). =P

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