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  1. AP Calculus
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How to determine convergence/divergence using the nth Term Test?

  1. Find lim⁡n→∞an\lim_{n \to \infty} a_nlimn→∞​an​. 2. If the limit is not 0, the series diverges. 3. If the limit is 0, the test is inconclusive.
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How to determine convergence/divergence using the nth Term Test?

  1. Find lim⁡n→∞an\lim_{n \to \infty} a_nlimn→∞​an​. 2. If the limit is not 0, the series diverges. 3. If the limit is 0, the test is inconclusive.

How to apply the Limit Comparison Test?

  1. Choose a series ∑bn\sum b_n∑bn​ to compare with. 2. Find lim⁡n→∞anbn=c\lim_{n \to \infty} \frac{a_n}{b_n} = climn→∞​bn​an​​=c. 3. If ccc is finite and positive, both series converge or diverge together.

How to apply the Direct Comparison Test?

  1. Find a series to compare. 2. Establish inequality. 3. If larger converges, smaller converges. If smaller diverges, larger diverges.

How to apply the Integral Test?

  1. Verify f(x)f(x)f(x) is continuous, positive, decreasing. 2. Evaluate ∫1∞f(x)dx\int_{1}^{\infty} f(x) dx∫1∞​f(x)dx. 3. If the integral converges, the series converges. If the integral diverges, the series diverges.

How to apply the Alternating Series Test?

  1. Check if terms decrease in absolute value. 2. Check if lim⁡n→∞an=0\lim_{n \to \infty} a_n = 0limn→∞​an​=0. 3. If both conditions are met, the series converges.

How to apply the Ratio Test?

  1. Find lim⁡n→∞∣an+1an∣=L\lim_{n \to \infty} |\frac{a_{n+1}}{a_n}| = Llimn→∞​∣an​an+1​​∣=L. 2. If L<1L < 1L<1, the series converges. 3. If L>1L > 1L>1, the series diverges. 4. If L=1L = 1L=1, the test is inconclusive.

How to find the radius of convergence of a power series?

  1. Use the Ratio Test. 2. Solve for ∣x−c∣<R|x - c| < R∣x−c∣<R. 3. RRR is the radius of convergence.

How to find the interval of convergence of a power series?

  1. Find the radius of convergence, R. 2. Test the endpoints c−Rc - Rc−R and c+Rc + Rc+R for convergence. 3. Write the interval, including or excluding endpoints based on convergence.

How to estimate the sum of an alternating series with a specified error?

  1. Use Alternating Series Error Bound: ∣Error∣≤∣an+1∣|Error| \leq |a_{n+1}|∣Error∣≤∣an+1​∣. 2. Find the smallest nnn such that ∣an+1∣|a_{n+1}|∣an+1​∣ is less than the specified error. 3. Sum the first nnn terms.

How to find a Taylor series for a given function?

  1. Find derivatives of the function. 2. Evaluate derivatives at the center. 3. Plug into the Taylor series formula: ∑n=0∞f(n)(c)n!(x−c)n\sum_{n=0}^{\infty} \frac{f^{(n)}(c)}{n!}(x-c)^n∑n=0∞​n!f(n)(c)​(x−c)n.

Explain the nth Term Test for Divergence.

If lim⁡n→∞an≠0\lim_{n \to \infty} a_n \neq 0limn→∞​an​=0, then the series ∑an\sum a_n∑an​ diverges.

Explain the Limit Comparison Test.

If lim⁡n→∞anbn=c\lim_{n \to \infty} \frac{a_n}{b_n} = climn→∞​bn​an​​=c, where ccc is finite and positive, then ∑an\sum a_n∑an​ and ∑bn\sum b_n∑bn​ either both converge or both diverge.

Explain the Direct Comparison Test.

If 0≤an≤bn0 \leq a_n \leq b_n0≤an​≤bn​ and ∑bn\sum b_n∑bn​ converges, then ∑an\sum a_n∑an​ converges. If an≥bn≥0a_n \geq b_n \geq 0an​≥bn​≥0 and ∑bn\sum b_n∑bn​ diverges, then ∑an\sum a_n∑an​ diverges.

Explain the Integral Test.

If f(x)f(x)f(x) is continuous, positive, and decreasing for x≥1x \geq 1x≥1, then ∑n=1∞f(n)\sum_{n=1}^{\infty} f(n)∑n=1∞​f(n) and ∫1∞f(x)dx\int_{1}^{\infty} f(x) dx∫1∞​f(x)dx either both converge or both diverge.

Explain the Alternating Series Test.

If ana_nan​ is decreasing and lim⁡n→∞an=0\lim_{n \to \infty} a_n = 0limn→∞​an​=0, then the alternating series ∑(−1)nan\sum (-1)^n a_n∑(−1)nan​ converges.

Explain the Ratio Test.

If lim⁡n→∞∣an+1an∣=L\lim_{n \to \infty} |\frac{a_{n+1}}{a_n}| = Llimn→∞​∣an​an+1​​∣=L, then the series converges if L<1L < 1L<1, diverges if L>1L > 1L>1, and is inconclusive if L=1L = 1L=1.

Explain the concept of radius of convergence.

The distance from the center of a power series within which the series converges.

Explain the Alternating Series Error Bound.

The error in approximating an alternating series is less than or equal to the absolute value of the first omitted term.

Explain the Lagrange Error Bound.

The error in approximating a function using a Taylor polynomial is bounded by the Lagrange Error Bound, which depends on the (n+1)th derivative.

What does it mean for a series to converge absolutely?

A series ∑an\sum a_n∑an​ converges absolutely if ∑∣an∣\sum |a_n|∑∣an​∣ converges.

What does it mean for a series to converge conditionally?

A series ∑an\sum a_n∑an​ converges conditionally if ∑an\sum a_n∑an​ converges but ∑∣an∣\sum |a_n|∑∣an​∣ diverges.

Define a sequence.

A function whose domain is the set of natural numbers.

Define a series.

The sum of the terms of a sequence.

What is a convergent sequence/series?

Terms approach a specific value (the limit).

What is a divergent sequence/series?

Terms do not approach a specific value; the sum is infinite.

Define an arithmetic sequence.

Sequence with a constant difference between consecutive terms.

Define a geometric sequence.

Sequence where each term is the previous term multiplied by a constant ratio.

Define a harmonic series.

Series where terms are reciprocals of positive integers.

Define a power series.

Series of the form ∑an(x−c)n\sum a_n(x-c)^n∑an​(x−c)n where ana_nan​ are constants and ccc is a constant.

Define an alternating series.

Series where the terms alternate in sign.

Define a Taylor series.

Representation of a function as an infinite sum of terms, with each term being a polynomial function of a single variable.

Define a Maclaurin series.

A Taylor series centered at 0.