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

Feb2313 09:24 AM
micromass

1 
39,999 
Accidentally I wrote in the wolfram f(x) = f(1/x) the the wolfram give me the solution for this equation (f(x) =...

T 01:09 PM
HallsofIvy

2 
120 
Hi
I am currently reading a book where this showed up:
The author gave a ##3## parameter equation (note ##Y##...

T 12:20 AM
Red_CCF

1 
272 
i'm trying to integrate this:
$$W=\frac{ε}{2}\int{\vec{∇}\cdot\vec{E})Vdτ}$$
where ε is a constant, E= ∇V, τ is...

Y 09:35 PM
Simon Bridge

4 
164 
I am working on the derivation of the angular momentum squared operator (in quantum mech.) and there is one step that...

Y 07:53 PM
hideelo

2 
70 
\int \frac{d}{dx}f(x)dx = f(x) + C_x \iint \frac{d^2}{dx^2}f(x)dx^2 = f(x) + xC_x + C_{xx}
\int...

Y 02:48 PM
Mark44

7 
216 
Hey guys, I'm really really confused on how we come about the plane z = x  y. I always have been and it's proving to...

Y 08:47 AM
HallsofIvy

2 
106 
Hello,
I've come across equations where people use the approximation
\int_0^1 \exp(f(x))\, dx \approx \exp \left(...

Y 05:17 AM
Irid

0 
71 
I'm brushing up on calculus. I don't see how this derivative works.
x(t) = A cos(ωt  \varphi)
v(t) = dx / dt = ...

Apr1414 06:49 PM
jbunniii

1 
112 
I understand how to use it, but I'm just getting really confused on when you use it? Is there a way you can look at...

Apr1414 06:45 PM
Jhenrique

4 
210 
Hi!
I am having trouble following the derivation from Euler's Equation to Bernoulli's Equation. The trouble lies in...

Apr1414 01:38 PM
Einj

3 
191 
how do I find the derivative of tanh^1(sinh(2x))
do I just find derivative of tanh^1(x) this then substitute...

Apr1314 08:14 PM
AMenendez

2 
178 
please tell me if i did this correctly:
task: i'm trying to divide the differential dA by dV
where.. dA =...

Apr1314 03:57 PM
HallsofIvy

3 
147 
Hi all ! I'm new here :)
So I'm facing some confusions here regarding integration by parts. While surfing through...

Apr1314 01:10 AM
O.CModderz

9 
318 
the coordinates of cycloide are
##x= a (\theta sin \theta)##
##y= a(cos \theta 1)##
If i use ##\theta =\omega...

Apr1214 10:16 PM
Simon Bridge

3 
176 
How is this limit evaluated?
\lim_{k>0}\frac{sin(\pi k)}{sin(\frac{\pi k}{N})}
I know that it is N, but I...

Apr1214 09:04 PM
Jyan

0 
149 
A uniformly convergent sequence of continuous functions converges to a continuous function.
I have no problem with...

Apr1114 01:26 AM
GenePeer

5 
494 
Hello. My first time posting here. So... My question is kinda hard to explain but I will try to. So we all know about...

Apr914 02:00 PM
AlfredB

0 
173 
Hello,
Consider two particles which interact via a Gaussian potential:
V(\mathbf{x}) = \exp(\mathbf{x}^2)
I...

Apr914 11:08 AM
Irid

0 
143 
Hi,
I'm doing this integration:
I = ∫^{1}_{1}1/(\pi√1x2)dx
I made the substitution x = cosθ, and I'm fine...

Apr814 11:03 AM
jbunniii

1 
219 
I'm not sure which category this post actually belongs to, or if the title of this post is even accurate. I guessed...

Apr814 03:37 AM
micromass

19 
658 
So this is a theoretical question I am not sure about with partial derivatives.
Say we have function x(i,j) with ...

Apr814 01:33 AM
chicago77

2 
230 
hey pf!
i have a few question about the physical intuition for divergence, gradient, and curl. before asking, i'll...

Apr714 11:35 PM
joshmccraney

8 
312 
Is it necessary for some point ##x## of the function to be saddle that
##f'(x)=0##?

Apr714 04:34 PM
Mark44

3 
207 
I'm looking for a way to write down an analytic approximation for the following integral:
\int_0^\infty \frac{k...

Apr714 03:04 PM
csmallw

2 
247 
Hello all,
I have the following integration:
\int_{\infty}^{\infty}e^{j2\pi...

Apr714 02:23 PM
S_David

3 
275 
Function ##f(x)=x^4## has minimum at ##x=0##.
## f'(x)=4x^3##
##f'(0)=0##
##f''(x)=12x^2##
##f''(0)=0##...

Apr714 10:08 AM
HallsofIvy

2 
204 
I have been trying to follow how the complex Fourier coefficients are obtained; the reference I am using is at...

Apr614 05:08 PM
jellicorse

4 
228 
Hi guys, so I'm trying to create this thing that gets accelerometer values and integrate those values at about 25...

Apr614 03:17 PM
mathman

1 
262 
I saw in a question related to Signals and systems that the limits were taken from 5 to 10+ where the signs were in...

Apr514 08:45 PM
Mark44

5 
253 
Suppose ##f^{\prime\prime}## is continuous on an open interval that contains x = c
1. If ##f^{\prime}(c)=0## and...

Apr514 11:27 AM
22990atinesh

3 
236 
I have a question about optimization. When we apply subgradient method to a differential optimization problem, will it...

Apr514 10:53 AM
peterlam

0 
188 
The popular fundamental theorem of calculus states that \int_{x_0}^{x_1} \frac{df}{dx}(x)dx = f(x_1)f(x_0) But I...

Apr514 04:51 AM
Jhenrique

8 
370 
hey pf!
i had a question. namely, in the continuity equation we see that \frac{\partial}{\partial t}\iiint_V \rho...

Apr414 07:14 PM
joshmccraney

2 
236 
I found this identity in the wiki
https://upload.wikimedia.org/math/3/3/8/3381de258dc7b9d8733d05011c9811eb.png...

Apr414 07:09 PM
Jhenrique

0 
197 
I'm having a little bit of trouble understanding the equation of a cone..
It is given by (x^2)/(a^2) + (y^2)/(b^2)...

Apr414 05:05 PM
gopher_p

1 
212 
Hi! :smile:
I have the following integral
\int^{∞}_{∞} \frac{\delta^{n}}{\delta a}f(a,b,c)da
there is any...

Apr414 03:37 PM
mathman

1 
268 
Dear All,
I am unable to understand a simple mathematics relation. I spent 23 hours to Google multivariable...

Apr414 03:34 PM
mathman

1 
258 
The graph of a differentiable function y=f(x) is
1. concave up on an interval I if f' is increasing on I.
2....

Apr414 11:06 AM
22990atinesh

9 
356 
Like we have the total differential of a function:
http://s18.postimg.org/oj87l7x5l/imagem.png
I was thinking, why...

Apr414 10:44 AM
Mark44

5 
358 
While watching a recent Youtube video on Marxian crisis theory and the Tendency Of The Rate Of Profit To Fall, I...

Apr314 04:11 AM
willem2

2 
299 