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 27.2
Incorrect: Your answer is incorrect. 0.9 -33.2
Correct: Your answer is correct. 1.1 297.0
Incorrect: Your answer is incorrect. 0.99 -303.0
Changed: Your submitted answer was incorrect. Your current answer has not been submitted. 1.01 2997.0
Incorrect: Your answer is incorrect. 0.999 -3003.0
Changed: Your submitted answer was incorrect. Your current answer has not been submitted. 1.001 29997.0
Incorrect: Your answer is incorrect. 0.9999 -30003.0
Correct: Your answer is correct. 1.0001 299997
0.99999
Correct: Your answer is correct. 1.00001 2999997
Incorrect: Your answer is incorrect.
Solution
Let's first analyze the function:
We are interested in evaluating the left-hand limit and the right-hand limit . To do this, we'll examine the behavior of near by substituting values approaching 1 from the left (e.g., 0.5, 0.9, 0.99, etc.) and from the right (e.g., 1.5, 1.1, 1.01, etc.).
Function Breakdown:
The function can be rewritten as: Thus, has a discontinuity at because the denominator approaches zero as approaches 1.
For the Left-Hand Limit :
- As , becomes a small negative number, and is positive, so the overall expression for tends to negative infinity.
For the Right-Hand Limit :
- As , becomes a small positive number, and remains positive, so the overall expression for tends to positive infinity.
Now let's use the table values provided to evaluate the function near :
x | f(x) |
---|---|
0.5 | -10.3 |
0.9 | -33.2 |
0.99 | -303.0 |
0.999 | -3003.0 |
0.9999 | -30003.0 |
1.0001 | 299997 |
1.001 | 29997.0 |
1.01 | 2997.0 |
1.1 | 297.0 |
1.5 | 27.2 |
From this table, we observe the following:
- As approaches 1 from the left (values like 0.9, 0.99, 0.999), the values of become very large negative numbers, indicating the left-hand limit tends to negative infinity.
- As approaches 1 from the right (values like 1.1, 1.01, 1.0001), the values of become very large positive numbers, indicating the right-hand limit tends to positive infinity.
Thus:
Would you like to explore more details, or have any further questions on this?
Follow-up questions:
- How would the graph of behave near ?
- What happens if we take the limit of as approaches 1 from different directions, say from or ?
- Can we apply L'Hopital's Rule to evaluate the limit as ?
- How would the behavior change if the function were instead of ?
- What is the role of the cubic term in determining the limits?
Tip:
Always carefully consider the sign of the denominator as approaches the point where the function is undefined. It helps determine whether the function tends to or .
Ask a new question for Free
By Image
Drop file here or Click Here to upload
Math Problem Analysis
Mathematical Concepts
Limits
Discontinuity
Rational Functions
Formulas
f(x) = 9 / (x^3 - 1)
f(x) = 9 / ((x - 1)(x^2 + x + 1))
Theorems
Limit laws
Discontinuity in rational functions
Suitable Grade Level
Grades 11-12