Chapter 9: Problem 65
Determine the convergence or divergence of the series. \(\sum_{n=0}^{\infty} \frac{1}{4^{n}}\)
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Chapter 9: Problem 65
Determine the convergence or divergence of the series. \(\sum_{n=0}^{\infty} \frac{1}{4^{n}}\)
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Consider the sequence \(\left\\{a_{n}\right\\}=\left\\{\frac{1}{n} \sum_{k=1}^{n} \frac{1}{1+(k / n)}\right\\}\). (a) Write the first five terms of \(\left\\{a_{n}\right\\}\). (b) Show that \(\lim _{n \rightarrow \infty} a_{n}=\ln 2\) by interpreting \(a_{n}\) as a Riemann sum of a definite integral.
Find the values of \(x\) for which the infinite series \(1+2 x+x^{2}+2 x^{3}+x^{4}+2 x^{5}+x^{6}+\cdots\) converges. What is the sum when the series converges?
Investigation (a) Find the power series centered at 0 for the function \(f(x)=\frac{\ln \left(x^{2}+1\right)}{x^{2}}\) (b) Use a graphing utility to graph \(f\) and the eighth-degree Taylor polynomial \(P_{8}(x)\) for \(f\). (c) Complete the table, where \(F(x)=\int_{0}^{x} \frac{\ln \left(t^{2}+1\right)}{t^{2}} d t\) and \(G(x)=\int_{0}^{x} P_{8}(t) d t\) (d) Describe the relationship between the graphs of \(f\) and \(P_{8}\) and the results given in the table in part (c).
Probability A fair coin is tossed repeatedly. The probability that the first head occurs on the \(n\) th toss is given by \(P(n)=\left(\frac{1}{2}\right)^{n}\), where \(n \geq 1\) (a) Show that \(\sum_{n=1}^{\infty}\left(\frac{1}{2}\right)^{n}=1\). (b) The expected number of tosses required until the first head occurs in the experiment is given by \(\sum_{n=1}^{\infty} n\left(\frac{1}{2}\right)^{n}\) Is this series geometric? (c) Use a computer algebra system to find the sum in part (b).
Given two infinite series \(\sum a_{n}\) and \(\sum b_{n}\) such that \(\sum a_{n}\) converges and \(\Sigma b_{n}\) diverges, prove that \(\Sigma\left(a_{n}+b_{n}\right)\) diverges.
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