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E Be
  • Member for 9 years, 9 months
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10 votes
5 answers
983 views

Calculate $\int _0^\infty \frac{\ln x}{(x^2+1)^2}dx$

5 votes
3 answers
2k views

spherical segment volume

4 votes
1 answer
7k views

Show that if $P(0 \leq X \leq c)=1$ then $Var(X) \leq \frac{c^2}{4}$

4 votes
1 answer
113 views

meaning of in-homogenous term in the wave function

4 votes
1 answer
417 views

Fourier series of $\sin(x)$

3 votes
1 answer
77 views

Fourier series to a function

3 votes
1 answer
258 views

Fourier series of f(x)

3 votes
0 answers
445 views

Find a series solution to $(x^2-2)y''+6xy'+4y=0$.

3 votes
2 answers
18k views

Find the Laurent series of $f(z)=\frac{1}{z(1-z)}$

2 votes
6 answers
310 views

Integrate $\int_{-\infty}^\infty xe^{-\alpha x^2+\beta x}dx$ [duplicate]

2 votes
3 answers
353 views

Can I use the Dirichlet's test to prove the convergence of $\sum_{n=1}^N \frac{e^{in}}{n}$?

2 votes
2 answers
7k views

Difference between 'stable node' and 'stable spiral'

2 votes
5 answers
139 views

What is the sum of $\sum_{n=1}^\infty (n^2+n^3)x^{n-1}$?

2 votes
1 answer
163 views

Find $\mathcal{L}^{-1}\frac{s}{s^2-6s+9}$

2 votes
1 answer
56 views

simplifying an expression with even and odd integers

2 votes
0 answers
25 views

Iterating a correct Sigma sign to odd zeros.

2 votes
1 answer
85 views

Calc $\frac{1}{\sqrt{2\pi}}\int_{-\infty}^\infty -\frac{t}{1+t^2}(\delta (\omega-t-\pi)-\delta(\omega-t+\pi))dt$

2 votes
1 answer
46 views

2 similar question about how to find the $a_n$s and $b_n$ of a Fourier series

2 votes
4 answers
450 views

Does the series $\sum (1+n^2)^{-1/4}$ converge or diverge?

1 vote
1 answer
115 views

Calculate $\int _0^\infty \frac{\sin^2 (\pi \omega)}{(\omega ^2 -1)^2}d \omega$

1 vote
2 answers
6k views

What is the $L$ in the Fourier series term?

1 vote
1 answer
43 views

the jump in $\ddot y$, Laplace transform

1 vote
2 answers
1k views

How to find $\int {t^n \, e^{t}}\mathrm dt$?

1 vote
1 answer
26 views

Any closed formula for $\mathcal{L}\big(u_c(t)\cdot f(t)\big) $?

1 vote
1 answer
107 views

Find the Taylor expansion of $\frac{1}{x^2+2x-3}$ around $x=-1$.

1 vote
1 answer
197 views

Evaluating complex functions integrals over closed curves

1 vote
1 answer
174 views

Partial fractions for $\left (\frac{z^2+1}{z^2-1} \right )^2$

1 vote
2 answers
4k views

Partial fractions for $\frac{1}{(z^2+1)^2}$

1 vote
2 answers
31 views

Show that $\sum_{n=0}^\infty\frac{3 n+6 i}{(1+2 i)^n}$ converges.

1 vote
1 answer
97 views

what is $\frac{d}{d(ax)}f(x)$ and $\frac{d}{d(ax)}f(x)$