Compute the limit (exponents with variable)

  • Thread starter Thread starter PirateFan308
  • Start date Start date
  • Tags Tags
    Limit Variable
Click For Summary
SUMMARY

The discussion focuses on computing the limit of the sequence defined by the expression (3n + 17n + 3) / (4n + 5n - 2). Participants clarify that as n approaches infinity, both the numerator and denominator approach infinity, resulting in an indeterminate form of +∞ / +∞. The correct approach involves recognizing the need to analyze the leading terms of the polynomials, leading to the conclusion that the limit does not exist in a straightforward manner and requires further evaluation of the ratios of the leading coefficients.

PREREQUISITES
  • Understanding of limits in calculus
  • Familiarity with polynomial functions and their behavior as n approaches infinity
  • Knowledge of indeterminate forms in calculus
  • Basic algebraic manipulation of expressions
NEXT STEPS
  • Study L'Hôpital's Rule for resolving indeterminate forms
  • Learn about polynomial long division for limits
  • Explore the concept of leading coefficients in limits
  • Investigate exponential growth rates and their impact on limits
USEFUL FOR

Students studying calculus, mathematics educators, and anyone seeking to deepen their understanding of limits and indeterminate forms in sequences and functions.

PirateFan308
Messages
91
Reaction score
0

Homework Statement


Compute the limits of the following sequence (show your work):

3n+17n+3
4n5n-2

(sorry if it looks funny ... the top line is divided by the bottom line)

The Attempt at a Solution


I was thinking that I should get the exponents the same and add/subtract the exponents, but I don't remember how to, or if this is even possible.
 
Physics news on Phys.org
I think I figured out a bit more. I have learned that I can split up the limit, so it will look like:
(lim3n+1)(lim7n+3) ÷ (lim4n)(lim5n-2)

and each of these individual limits equals +∞.

So I have +∞ ÷ +∞. Does this still equal infinity, 0, or does not exist?
 
PirateFan308 said:
I think I figured out a bit more. I have learned that I can split up the limit, so it will look like:
(lim3n+1)(lim7n+3) ÷ (lim4n)(lim5n-2)

and each of these individual limits equals +∞.

So I have +∞ ÷ +∞. Does this still equal infinity, 0, or does not exist?

Try this. 2^n/3^n=(2/3)^n. What's the limit of that? How about 3^n/2^n? There's a reason why infinity/infinity is called 'indeterminant'.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
Replies
17
Views
4K
  • · Replies 14 ·
Replies
14
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
Replies
35
Views
5K
  • · Replies 9 ·
Replies
9
Views
2K