
Let \(f(x)= \begin{cases}0 & \text { for } 0 \leq x<2 \\ -(4-x) & \text { for } 2 \leq x \leq 4\end{cases}\)
- Compute the Fourier cosine coefficients for \(f(x)\).
- \(a_{0}=\)
- \(a_{n}=\)
- What are the values for the Fourier cosine series \(\frac{a_{0}}{2}+\sum_{n=1}^{\infty} a_{n} \cos \left(\frac{n \pi}{4} x\right)\) at the given points.
- \(x=2:\)
- \(x=-3\) :
- \(x=5:\)
5. If \(f(x)=\left\{\begin{array}{cc}0 & -2<x<0 \\ x & 0<x<2\end{array} \quad\right.\)is periodio of period 4 , and whose Fourier series is given by \(\frac{a_{0}}{2}+\sum_{n=1}^{2}\left[a_{n} \cos \left(\frac{n \pi}{2} x\right)+b_{n} \sin \left(\frac{n \pi}{2} x\right)\right], \quad\) find \(a_{n}\)A. \(\frac{2}{n^{2} \pi^{2}}\)B. \(\frac{(-1)^{n}-1}{n^{2} \pi^{2}}\)C. \(\frac{4}{n^{2} \pi^{2}}\)D. \(\frac{2}{n \pi}\)\(\mathbf{E}_{1} \frac{2\left((-1)^{n}-1\right)}{n^{2} \pi^{2}}\)F. \(\frac{4}{n \pi}\)6. Let \(f(x)-2 x-l\) on \([0,2]\). The Fourier sine series for \(f(x)\) is \(\sum_{w}^{n} b_{n} \sin \left(\frac{n \pi}{2} x\right)\), What is \(b, ?\)A. \(\frac{4}{3 \pi}\)B. \(\frac{2}{\pi}\)C. \(\frac{4}{\pi}\)D. \(\frac{-4}{3 \pi}\)E. \(\frac{-2}{\pi}\)F. \(\frac{-4}{\pi}\)7. Let \(f(x)\) be periodic...
Frequency-domain sampling. Consider the following discrete-time signal$$ x(n)= \begin{cases}a^{|n|}, & |n| \leq L \\ 0, & |n|>L\end{cases} $$where \(a=0.95\) and \(L=10\).(a) Compute and plot the signal \(x(n)\).(b) Show that$$ X(\omega)=\sum_{n=-\infty}^{\infty} x(n) e^{-j \omega n}=x(0)+2 \sum_{n-1}^{L} x(n) \cos \omega n $$Plot \(X(\omega)\) by computing it at \(\omega=\pi k / 100, k=0,1, \ldots, 100\).(c) Compute$$ c_{k}=\frac{1}{N} X\left(\frac{2 \pi}{N} K\right), \quad k=0,1, \ldots, N-1 $$for \(N=30\).(d) Determine and plot the signal$$ \tilde{x}(n)=\sum_{k=0}^{N-1} c k e^{j(2 \pi / N) k n} $$What is the...
Let \(\left.x_{(} t\right)=\left\{\begin{array}{rr}t, & 0 \leq t \leq 1 \\ -t, & -1 \leq t \leq 0\end{array}\right.\), be a periodic signal with fundamental period of \(T=2\) and Fourier series coefficients \(a_{k}\).a) Sketch the waveform of \(x(t)\) and \(\frac{d x(t)}{d t}\) b) Calculate \(a_{0}\) c) Determine the Fourier series representation of \(g(t)=\frac{d x(t)}{d t}d) Using the results from Part (c) and the property of continuous-time Fourier series to determine the Fourier series coefficients of \(x(t)\)
If the series \(\sum_{n=1}^{\infty} a_{n}\) converges and \(a_{n}>0\) for all \(n\), which of the following must be true?(A) \(\lim _{n \rightarrow \infty}\left|\frac{a_{n+1}}{a_{n}}\right|=0\)(B) \(\left|a_{n}\right|<1\)for all \(n\)(C) \(\sum_{n=1}^{\infty} a_{n}=0\)(D) \(\sum_{n=1}^{\infty} n a_{n}\) diverges.(E) \(\sum_{n=1}^{\infty} \frac{a_{n}}{n}\) converges.
Let f(x)={0−(4−x)for 0≤x<2,for 2≤x≤4. ∙ Compute the Fourier cosine coefficients for f(x).a0=an=What are the values for the Fourier cosine series a02 + ∑n = 1∞ancos(nπ4x) at the given points.x=2:x=−3:x=5:
Determine whether the series converges, and if so, find its sum. (1) \(\sum_{n=1}^{\infty} 3^{-n} 8^{n+1}\)\((2) \sum_{n=2}^{\infty} \frac{1}{n(n-1)}\)(3) \(\sum_{n=0}^{\infty}(-3)\left(\frac{2}{3}\right)^{2 n}\)(4) \(\sum_{n=1}^{\infty} \frac{1}{e^{2 n}}\)(5) \(\sum_{n=1}^{\infty} \ln \frac{n}{n+1}\)(6) \(\sum_{n=1}^{\infty}[\arctan (n+1)-\arctan n]\)(7) \(\sum_{n=1}^{\infty} \ln \left(\frac{n^{2}+4}{2 n^{2}+1}\right)\)(8) \(\sum_{n=1}^{\infty} \frac{1+2^{n}}{3^{n}}\)(9) \(\sum_{n=1}^{\infty}\left[\cos \frac{1}{n^{2}}-\cos \frac{1}{(n+1)^{2}}\right]\)
7. Use the Alternating Series Test to determine the convergence or divergence of the series a) \(\sum_{n=1}^{\infty} \frac{(-1)^{n} \sqrt{n}}{2 n+1}\)b) \(\sum_{n=1}^{\infty} \frac{(-1)^{n} n}{2 n-1}\)8. Use the Ratio Test or the Root Test to determine the convergence or divergence of the seriesa) \(\sum_{n=0}^{\infty}\left(\frac{4 n-1}{5 n+7}\right)^{n}\)b) \(\sum_{n=0}^{\infty} \frac{\pi^{n}}{n !}\)
Determine whether the series converges or diverges.(1) \(\sum_{n=1}^{\infty} \frac{e^{1 / n}}{n^{2}}\)(2) \(\sum_{n=1}^{\infty}\left(\frac{2}{\sqrt{n}}+\frac{(-1)^{n}}{3^{n+1}}\right)\)(3) \(\sum_{n=1}^{\infty} \frac{5-2 \sin n}{n}\)(4) \(\sum_{n=1}^{\infty} \frac{3+\cos n}{n^{3 / 2}}\)(5) \(\sum_{n=0}^{\infty} \frac{\sqrt{n^{2}+2}}{n^{4}+n^{2}+5}\)(6) \(\sum_{n=1}^{\infty=1}\left(1+\frac{1}{n}\right)^{n}\)(7) \(\sum_{n=1}^{\infty} \frac{n+1}{n 2^{n}}\)(8) \(\sum_{n=1}^{\infty} \frac{\arctan n}{n^{4}}\)(9) \(\sum_{n=1}^{\infty} n \sin \frac{1}{n}\)
find an expression for the area of the region under the graph f(x)=x^4 on the interval [1,7]. use right-Hand endpoints as sample points choices1. area \(=\lim _{n \rightarrow \infty} \sum_{i=1}^{n}\left(1+\frac{7 i}{n}\right)^{4} \frac{7}{n}\)2. area \(=\lim _{n \rightarrow \infty} \sum_{i=1}^{n}\left(1+\frac{9 i}{n}\right)^{4} \frac{6}{n}\)3. area \(=\lim _{n \rightarrow \infty} \sum_{i=1}^{n}\left(1+\frac{6 i}{n}\right)^{4} \frac{6}{n}\)4. area \(=\lim _{n \rightarrow \infty} \sum_{i=1}^{n}\left(1+\frac{7 i}{n}\right)^{4} \frac{6}{n}\)5. area \(=\lim _{n \rightarrow \infty} \sum_{i=1}^{n}\left(1+\frac{6 i}{n}\right)^{4} \frac{7}{n}\)6. area \(=\lim _{n \rightarrow \infty} \sum_{i=1}^{n}\left(1+\frac{9 i}{n}\right)^{4} \frac{7}{n}\)
1. Consider a geometric series of \(\sum_{n=1}^{\infty} g r^{n-1}\). Plot the \(\mathrm{n}\) -th term \(a_{n}\), and the partial sum \(s_{n}\) versus \(n\) under the following two conditions.i) with \(g=12\), and \(\mathrm{r}=2 / 3\),ii) with \(g=12\), and \(r=3 / 2\).Which of the (i) or (ii) converges? For the convergent one, approximate the total sum, i.e. \(\sum_{n=1}^{\infty} g r^{n-1}\) from your plot and draw a line on the plot to demonstrate this.2. Using the following inequality, find the value of \(\sum_{n=1}^{\infty} \frac{1}{n^{2}}\)...