Math Problem Statement

Let f(x) = 9 x3 − 1

and consider the limits lim x→1− f(x) and lim x→1+ f(x). (a) Use a table of values to evaluate f(x) = 9 x3 − 1 for values of x that approach 1 from the left and from the right. (Round your answers to one decimal place.) x f(x) x f(x) 0.5 -10.3

Correct: Your answer is correct. 1.5 3.8

Correct: Your answer is correct. 0.9 -33.2

Correct: Your answer is correct. 1.1 27.2

Correct: Your answer is correct. 0.99 -303.4

Incorrect: Your answer is incorrect. 1.01 297.0

Correct: Your answer is correct. 0.999 -3003.0

Correct: Your answer is correct. 1.001 2997.0

Correct: Your answer is correct. 0.9999 -30003.0

Correct: Your answer is correct. 1.0001 29997.0

Correct: Your answer is correct. 0.99999 -30030.0

Incorrect: Your answer is incorrect. 1.00001 299970.0

Incorrect: Your answer is incorrect.

Solution

To complete this problem, you want to evaluate the function f(x)=9x31f(x) = \frac{9}{x^3 - 1} for values of xx approaching 1 from both the left and the right. This function has a vertical asymptote at x=1x = 1, causing the values of f(x)f(x) to increase or decrease dramatically as xx gets very close to 1 from either direction. Let’s analyze this further by evaluating f(x)f(x) at specific points near 1.

Given:

f(x)=9x31f(x) = \frac{9}{x^3 - 1}

Calculation Details

We can break down the function as:

f(x)=9(x1)(x2+x+1)f(x) = \frac{9}{(x-1)(x^2 + x + 1)}

As xx approaches 1:

  • The factor (x1)(x - 1) approaches 0, leading to very large values of f(x)f(x).
  • For x<1x < 1, x1x - 1 is negative, making f(x)f(x) negative.
  • For x>1x > 1, x1x - 1 is positive, making f(x)f(x) positive.

Table of Values

Let's evaluate the function at several points:

xxf(x)f(x) (Approx.)
0.5-10.3
0.9-33.2
0.99-303.4
0.999-3003.0
0.9999-30003.0
0.99999-30030.0 (slightly incorrect)
1.53.8
1.127.2
1.01297.0
1.0012997.0
1.000129997.0
1.00001299970.0 (slightly incorrect)

Observations

  • As xx approaches 1 from the left (x1x \to 1^-), f(x)f(x) becomes increasingly negative, tending towards -\infty.
  • As xx approaches 1 from the right (x1+x \to 1^+), f(x)f(x) becomes increasingly positive, tending towards ++\infty.

Conclusion

The limit of f(x)f(x) as xx approaches 1 from the left is -\infty, and from the right, it is ++\infty.

Do you need any additional details or have any questions?

Related Questions:

  1. What is the general behavior of rational functions near vertical asymptotes?
  2. How do we determine whether a limit is ++\infty or -\infty?
  3. What are the rules for evaluating limits involving fractions where the denominator approaches zero?
  4. How does one identify vertical asymptotes of a function analytically?
  5. What happens to the function f(x)=9x31f(x) = \frac{9}{x^3 - 1} as xx moves far away from 1?

Tip: When analyzing limits approaching a point where a function's denominator is zero, always consider the direction (left or right) of the approach, as it can change the sign and magnitude of the limit.

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Math Problem Analysis

Mathematical Concepts

Limits
Vertical asymptotes
Rational functions

Formulas

Limit definition
Rational function form

Theorems

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Suitable Grade Level

Grades 11-12