Please post any and all homework or other textbookstyle problems in one of the Homework & Coursework Questions...

Feb2313 09:24 AM
micromass

1 
40,050 
I have a set of N data points defined over a periodic interval, 0\le x \le 1.
I made a discrete fast fourier...

Feb2612 05:27 AM
matteo86bo

0 
711 
Hi,
In high school, I was shown an unconventional but quicker way to find max/mins. I'm not sure how common it is...

Feb2512 01:56 PM
nth.gol

2 
828 
I have been working on a problem proposed in a math journal, and there is only one thing I need to figure out. Here...

Feb2512 01:27 PM
alexfloo

1 
1,018 
If C is a simple closed contour such that w lies interior to C, and n > 1, then
\int_{C} \frac{dz}{(zw)^n} = 0. I'm...

Feb2512 11:11 AM
Unit

5 
1,281 
Have the following question and just wondering if my solution is correct
Let g(x)= x^5+3x1. Show that there are no...

Feb2512 11:01 AM
Mark44

3 
937 
So I came across a problem that said to use usub to solve:
integral(x^4sinxdx)
But the only way I could think...

Feb2512 06:44 AM
tinytim

1 
988 
My textbook (Taylor, Classical Mechanics) and professor introduced the concept of \nabla_{1}
to mean "the gradient...

Feb2512 12:30 AM
lugita15

3 
1,093 
I posted a problem called "estimating eigenvalue of perturbed matrix" in the section 'Linear and abstract algebra'...

Feb2412 10:54 PM
julian

2 
649 
We can show that
\int_{0}^\infty e^{kx}dx=\frac{1}{k}
for real $$k>0.$$
Does this result hold for $$\Re...

Feb2412 05:02 PM
Charles49

2 
853 
I'm curious if 1/x ~ 0. Technically by the definition I know it's not since lim x→∞ (1/x)/0 = ∞. But I feel like it...

Feb2412 03:20 PM
alexfloo

8 
1,138 
On a quiz, a true/false statement was given along the lines of:
"The gradient is a specific example of a...

Feb2412 03:10 PM
genericusrnme

12 
1,642 
Ok I can do the integral and see that it is equal to 2∏i, but thinking about it in terms of 'adding up' all the points...

Feb2412 09:26 AM
Bacle2

22 
2,533 
The stupid question of the day.
Is it fair to say that\frac{du}{dx} = \frac 1 {dx/du}
since this comes (I think)...

Feb2412 07:36 AM
dodo

2 
1,185 
I am having a hard time understanding how to parametrize the function y = sin(x) into component form (i,j).

Feb2412 07:06 AM
HallsofIvy

4 
1,075 
http://en.wikiversity.org/wiki/The_necessities_in_DSP
It seems great, but I don't know really. I think someone can...

Feb2312 10:04 PM
Ask4material

0 
863 
I actually made this question up while studying some chemistry. The problem is easy to visualize, but I'm trying to...

Feb2312 07:31 PM
Bipolarity

12 
1,087 
I understand everything in the proof except the last step I have written here. What comes after, I understand.
How...

Feb2312 10:02 AM
RUMarine

4 
1,144 
"In his studies on Fourier Series, W.H.Young has analyzed certain convex functions \Phi:IR\rightarrow\bar{IR}^{+}...

Feb2312 09:05 AM
fderingoz

0 
1,144 
Total variation is defined by
\Delta f=\delta f+\Delta x
For example f(x,y)=yx, y=y(x)
\Delta f=x\delta...

Feb2312 06:55 AM
matematikuvol

2 
1,033 
Hi,
How can I set a table in mathematica to count by a specified value, rather than the preset 1. For example, if I...

Feb2212 08:08 PM
iceblits

0 
874 
Wondering whether somebody could help me with a quick integral??
dp/dt = ap(1(p^2/q^2))
initial condition p(0) =...

Feb2212 04:23 PM
phyzguy

3 
1,141 
I wonder why z^(1/2) cannot be expanded in Laurent series with center z=0. Anyone knows?

Feb2212 03:30 PM
jackmell

2 
1,031 
Hello, I am just starting to learn limit evaluation techniques. I am unsure of the method used in this case.
(x^3 +...

Feb2212 10:14 AM
qazi75

5 
1,075 
note that by limit I mean the calculus operation, as in limf(x) as x>a.
I was playing around with numbers earlier...

Feb2212 08:52 AM
HallsofIvy

10 
5,523 
Hi all,
I have a set of data that is number of counts  vs  angle. I need one angle for a calculation. I need to...

Feb2212 01:16 AM
chloealex88

0 
618 
http://www.math.northwestern.edu/courses/placement/220_Self_Placement.pdf
Question 7 here involves a function with...

Feb2112 02:14 PM
Rasalhague

4 
1,067 
Aloha!
This is my first post, and I hope that I am posting in the correct area...
I need help with a math...

Feb2112 01:05 PM
T.A. Zenaide

6 
1,354 
I see equations of the form,
y=\int_{\infty }^{t}{F\left( x \right)}dx
a lot in my texts.
What exactly does...

Feb2112 11:44 AM
Char. Limit

3 
1,033 
The text book used in one of my courses talks about expanding functions in powers of 1/z aka negative powers of z.
...

Feb2012 02:44 PM
Harudoz

2 
1,945 
Hi,
In my fluids work I have come to integrals of the type:
\int_{0}^{\infty}\frac{e^{ikx}}{ak^{2}+bk+c}dk
I...

Feb2012 04:41 AM
hunt_mat

4 
1,100 
Say we are solving an indefinite integral ∫x√(2x+1) dx.
According to the textbook, the solution goes like this.
...

Feb2012 02:55 AM
Chsoviz0716

4 
1,259 
I am checking my homework with mathematica, but sometimes when I write stuff like
D , which is supposed to give me...

Feb1912 08:53 PM
lurflurf

1 
1,070 
greetings . we have the integral :
I(s)=\int_{0}^{\infty}\frac{s(E_{s}(x^{s})1)x}{x(e^{x}1)}dx
which is...

Feb1912 07:18 PM
mmzaj

2 
1,113 
I need to solve the following problem for a school assignment.
Let λ(t) denote the failuer rate of a system at time...

Feb1912 06:04 PM
Char. Limit

7 
1,181 
What I know from the chain rule is that if y and u are differentiable with respect to x then dy/dx = (dy/du)*(du/dx)
...

Feb1912 04:47 PM
alexfloo

5 
999 
Hello guys,
would you please check the solution attached with this post and whether it's right or wrong ???
if...

Feb1912 03:29 PM
Mechano

4 
1,104 
I was reading a section on vector fields and realized I am confused about how to take partials of vector quantities. ...

Feb1912 12:44 PM
The Head

10 
1,810 
Hi, I need a 3variable function f(x,y,z) with the following properties:
Denote fij=∂f2/∂i∂j.
1, f(x,y,z) must...

Feb1912 11:31 AM
loveinla

0 
833 
Is the imaginary axis considered a closed curve on the Riemann Sphere?

Feb1812 05:17 PM
lavinia

1 
924 
A function defined on ℝ is continuous at x if given ε, there is a δ such that f(x)f(y)<ε whenever xy<δ. Does...

Feb1712 07:42 PM
Flying_Goat

3 
1,007 