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

Feb2313 09:24 AM
micromass

1 
46,290 
I am using the PDF for lognormal distribution, which I'm referencing off the wikipedia page:
here. I am integrating...

Dec713 06:35 PM
oneamp

2 
572 
http://i.imgur.com/rTf1iaC.png
If instead of evaluating the above line integral in counterclockwise direction, I...

Dec713 08:33 AM
vanhees71

7 
892 
I am trying to compute the determinant of the Jacobian matrix of
the ndimensional spherical coordinates.
i will...

Dec613 01:24 PM
hedipaldi

0 
539 
Given a function f(x(t, s) y(t, s)), if is possible to compact
\frac{∂f}{∂t}=\frac{∂f}{∂x}...

Dec513 07:15 AM
Jhenrique

5 
694 
Hello guys, I am quite unsure in how to start the modeling for population. If I define y as the number of infected...

Dec513 01:40 AM
elitewarr

4 
644 
I have run into some situations where I need to scale a number by an infinitesimal amount and would like to know the...

Dec413 08:33 PM
tanus5

10 
699 
Hi,
I have been stuck on a problem for a while now (3.24 part c).
My attempt is as follows:
Internal virtual...

Dec413 04:35 PM
c0der

2 
789 
Let L be a forward operator and M be its adjoint defined using the inner product (f,Lg)=(Mf,g). Typically integration...

Dec413 04:13 PM
seanobeano

0 
673 
Assume we have a number ##S_0##. For ##i=1..n## define$$S_i=\begin{cases}(1+b)S_{i1}\text{ with probability...

Dec413 03:59 PM
mathman

1 
492 
If function is ##f(x,y)=f(x,y)##, is then
##\int^{a}_{a}\int^{a}_{a}f(x,y)dxdy=0##?
Thanks for answer.

Dec413 12:53 PM
LagrangeEuler

6 
622 
My book loves to represent the delta function as:
δ(rr')=∫∞∞exp(i(rr')k)dk
Now I can understand this formula...

Dec413 05:42 AM
pwsnafu

1 
538 
Hello!
Exist a general formula to idea of lagrange multiplier, a compact formula that is possible to extract the...

Dec313 01:45 PM
Jhenrique

0 
405 
is there a closed form solution for this double integral?
\int^{2}_{1}\int^{3}_{4}\sqrt{1+4x^{2}+4y^{2}}dydx

Dec313 10:36 AM
mabauti

5 
829 
Is it possible to formulate the second derivate trough of a tree diagram, as we do with a first derivative? If yes,...

Dec313 06:06 AM
Jhenrique

5 
738 
Hello there. I recently installed the Physics Forums app and could not find the homework section in the categories so...

Dec213 06:33 PM
Mark44

2 
578 
Hey guys. I am having some trouble visualizing one aspect of the Second derivative test in the 2 variable case...

Dec213 04:03 AM
Phoeniyx

8 
734 
In the process of calculating the integral \int_0^{2\pi}\frac{\sin{x} \cos{x}}{\sin{x}+\cos{x}}dx by contour...

Dec213 04:01 AM
jackmell

8 
802 
I know y is a function of x y=f\left(x\right)]
with two known boundary conditions, that is f\left(x=A\right)=C
and...

Dec113 04:39 PM
JulieK

3 
558 
If one uses Stokes' theorem and if two oriented surfaces S1 and S2 share a boundary ∂s then the flux integral of...

Dec113 11:03 AM
Gridvvk

0 
473 
limn→∞(\frac{1}{n+1}+\frac{1}{n+2}+...+\frac{1}{4n})
Hi, when I first looked at this limit I thought that the...

Nov3013 06:48 PM
lurflurf

7 
596 
It's easy to show that \frac{dy}{dx} of y = ln(ax) where a \in ℝ, a > 0 is always \frac{1}{x} :
y = ln(ax)
y =...

Nov3013 01:20 PM
Mark44

4 
614 
I just recently discovered for myself this weird graph, can anyone explain to me what is exactly happening here. I...

Nov2913 07:28 PM
lurflurf

2 
640 
I learned how to integrate it using the complex plane and semi circle contours but I was wondering if there is a way...

Nov2913 06:11 PM
lurflurf

5 
1,283 
In the context of my work (linear differential equations), it can not be zero. But why?

Nov2913 05:18 PM
gikiian

8 
698 
I would like to get an answer or pointers to suitable material, on the following question:
I know that ∫f(x)2dx...

Nov2913 03:09 PM
Simon Bridge

5 
746 
hello,
i have a question about an explanation of integration as finding the area under a curve. I don't have any...

Nov2913 02:49 PM
BOAS

4 
559 
In my high school Calculus course, I've encountered several optimization problems involving the area of a circle and I...

Nov2913 02:31 PM
tinytim

3 
571 
* I know this is a very long post but it would mean the world to me if you could read it. I would really appreciate...

Nov2913 10:39 AM
Office_Shredder

8 
1,006 
Hi,
I have a basic question about convergence.
I have two sequences, x1, x2, ... and y1, y2, ..., where yn =...

Nov2813 11:52 AM
R136a1

7 
547 
Hey. There's one thing I've always been wondering about when it comes to deriving the expression for the moment of...

Nov2713 02:06 PM
Nikitin

2 
853 
Dear Forum :
I hung up with a integration
http://ppt.cc/mIpV
Can it be deduced to a simpler form?
The...

Nov2713 01:49 PM
Bill Simpson

4 
801 
Se a function f(x(t, s), y(t, s)) have as derivative with respect to t:
\frac{df}{dt}=\frac{df}{dx}...

Nov2713 10:48 AM
Jhenrique

25 
1,303 
I am completely self taught in Calculus, but I would like to have a better understanding of it before I go to College....

Nov2713 02:41 AM
SteamKing

5 
614 
While doing work, I always see notation like:
F(x) = ∫0xf(t)dt  first equation
F(x) = ∫1xf(t)dt
What is the...

Nov2613 06:47 PM
Office_Shredder

2 
529 
My tutor showed me something today, and I still can't completely wrap my head around why it makes sense. Consider the...

Nov2613 05:56 PM
fzero

1 
652 
Hello!
What calculus textbook do you recommend for microbiology major or other biology majors?
I heard good...

Nov2513 04:08 PM
cpscdave

1 
698 
Hi,
I've questions about the Fredholm integral equation :
1. Is an following eq.
a(x)y(x) +...

Nov2513 03:28 PM
mathman

4 
595 
hey pf!
so if i have a vector field \vec{V} and i know \nabla \cdot \vec{V}=0 would i be able to express \vec{V}...

Nov2513 09:51 AM
pasmith

1 
460 
So \sqrt{306} is a pretty good approximation for Pi (=3.14155).
If you add 1/51, so that you have \sqrt{306+1/51}...

Nov2513 03:09 AM
CompuChip

1 
601 
Is there a proof that shows why indefinite integrals cannot be assessed when there are an infinite number of...

Nov2413 10:34 PM
MathewsMD

19 
1,363 