Math Problem Statement

Evaluate the following limits as x approaches infinity: 1. lim(x→∞) (a * x^89 - 7x + 59) / (c * x^89 - 59) 2. lim(x→∞) (a * x^89 - 7x + 59) / (c * x^86 - 59) 3. lim(x→∞) (a * x^86 - 7x + 59) / (c * x^89 - 59)

Solution

The image shows three limits that need to be evaluated as xx \to \infty. Let's break them down:

First Limit:

limxax897x+59cx8959\lim_{x \to \infty} \frac{a x^{89} - 7x + 59}{c x^{89} - 59}

  • The highest degree of xx in both the numerator and denominator is x89x^{89}.
  • As xx \to \infty, the lower degree terms (like 7x-7x, +59+59, and 59-59) become insignificant compared to the highest powers.

So, the limit simplifies to: limxax89cx89=ac\lim_{x \to \infty} \frac{a x^{89}}{c x^{89}} = \frac{a}{c}

Second Limit:

limxax897x+59cx8659\lim_{x \to \infty} \frac{a x^{89} - 7x + 59}{c x^{86} - 59}

  • Here, the highest degree term in the numerator is x89x^{89}, and the highest degree term in the denominator is x86x^{86}.
  • When the numerator's degree is higher than the denominator's, the limit tends to infinity.

Thus: limxax89cx86x3\lim_{x \to \infty} \frac{a x^{89}}{c x^{86}} \sim x^{3} \to \infty This limit tends to infinity.

Third Limit:

limxax867x+59cx8959\lim_{x \to \infty} \frac{a x^{86} - 7x + 59}{c x^{89} - 59}

  • In this case, the highest degree in the denominator is x89x^{89}, while the highest degree in the numerator is x86x^{86}.
  • When the denominator grows faster than the numerator, the entire fraction approaches 0 as xx \to \infty.

Thus: limxax86cx891x30\lim_{x \to \infty} \frac{a x^{86}}{c x^{89}} \sim \frac{1}{x^3} \to 0

Summary of Limits:

  1. ac\frac{a}{c}
  2. \infty
  3. 00

Would you like any more details on these calculations or further clarification?

Here are 5 related questions:

  1. How do we determine the dominant term when evaluating limits involving polynomials?
  2. What happens if the degree of the numerator is smaller than the denominator in limits to infinity?
  3. Why do constants become negligible as xx \to \infty?
  4. Can the limit of a rational function tend to a negative value? Under what circumstances?
  5. How do you handle limits with non-polynomial terms like exponential or trigonometric functions?

Tip: Always compare the highest degree terms in both the numerator and denominator when evaluating limits to infinity for rational functions.

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Math Problem Analysis

Mathematical Concepts

Limits at infinity
Polynomial functions
Dominant terms

Formulas

lim(x→∞) (a * x^n + ...) / (c * x^n + ...) = a/c, if degrees of numerator and denominator are equal
lim(x→∞) (a * x^n + ...) / (c * x^m + ...) = ∞ if degree of numerator > degree of denominator
lim(x→∞) (a * x^n + ...) / (c * x^m + ...) = 0 if degree of numerator < degree of denominator

Theorems

Limits of Rational Functions at Infinity

Suitable Grade Level

Grades 10-12, College Calculus