Use the Limit Comparison Test to determine whether the series converges.
Table of contents
- 0. Functions7h 52m
- Introduction to Functions16m
- Piecewise Functions10m
- Properties of Functions9m
- Common Functions1h 8m
- Transformations5m
- Combining Functions27m
- Exponent rules32m
- Exponential Functions28m
- Logarithmic Functions24m
- Properties of Logarithms34m
- Exponential & Logarithmic Equations35m
- Introduction to Trigonometric Functions38m
- Graphs of Trigonometric Functions44m
- Trigonometric Identities47m
- Inverse Trigonometric Functions48m
- 1. Limits and Continuity2h 2m
- 2. Intro to Derivatives1h 33m
- 3. Techniques of Differentiation3h 18m
- 4. Applications of Derivatives2h 38m
- 5. Graphical Applications of Derivatives6h 2m
- 6. Derivatives of Inverse, Exponential, & Logarithmic Functions2h 37m
- 7. Antiderivatives & Indefinite Integrals1h 26m
- 8. Definite Integrals4h 44m
- 9. Graphical Applications of Integrals2h 27m
- 10. Physics Applications of Integrals 3h 16m
- 11. Integrals of Inverse, Exponential, & Logarithmic Functions2h 34m
- 12. Techniques of Integration7h 39m
- 13. Intro to Differential Equations2h 55m
- 14. Sequences & Series5h 36m
- 15. Power Series2h 19m
- 16. Parametric Equations & Polar Coordinates7h 58m
14. Sequences & Series
Convergence Tests
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Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Use the Alternating Series Test to determine if the following series is conditionally convergent, absolutely convergent, or divergent.
A
Conditionally convergent
B
Divergent
C
Absolutely convergent

1
Step 1: Recall the Alternating Series Test (Leibniz Test). It states that an alternating series ∑(-1)^n a_n converges if: (1) a_n is positive, (2) a_n is decreasing, and (3) lim(n→∞) a_n = 0.
Step 2: Identify the sequence a_n in the given series. Here, a_n = (n+1)/ln(n). Check if a_n is positive for n ≥ 2 (since ln(n) is undefined for n=1). For n ≥ 2, ln(n) > 0, so a_n is positive.
Step 3: Check if a_n is decreasing. To do this, analyze the derivative of a_n = (n+1)/ln(n) or compare a_n and a_(n+1). If the derivative is negative or a_(n+1) < a_n for all n ≥ 2, then a_n is decreasing.
Step 4: Evaluate lim(n→∞) a_n. Compute lim(n→∞) (n+1)/ln(n). If this limit does not equal 0, the series fails the Alternating Series Test and is divergent.
Step 5: Since the series fails the Alternating Series Test (lim(n→∞) a_n ≠ 0), conclude that the series is divergent. Absolute convergence and conditional convergence are not applicable.
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