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

Feb2313 09:24 AM
micromass

1 
46,564 
OK, I'm new to multivariable calculus and I got this question in my exercises that asks me to integrate e^{2(x+y)} ...

Dec1313 01:30 PM
Shyan

3 
680 
I'd like to know what is a integral valued in one point (F(c)) and what is derivative valued in one interval...

Dec1313 05:48 AM
Jhenrique

0 
582 
I this old thread it mentions that the indefinite integral of f'(x)/f(x) is log(f(x))+C which means that there is...

Dec1213 04:10 PM
Mark44

30 
1,773 
How can I find the limit in question 7e and 7g?
Finding limits is difficult!:cry:

Dec1213 06:21 AM
haha1234

2 
641 
I am a graduate student and during my research I have come across this integration formula shows in attached image...

Dec1213 06:14 AM
hash054

9 
937 
Hi,
I figured out the only redundancy to my problem is this:
I'll start off with a simple case, where w1,w2 are...

Dec1213 01:59 AM
c0der

2 
787 
pi
∫sin^2(nx)/sin^2(x) dx
0
I tried using mathematical induction and did arrive at the correct result...

Dec1113 02:18 PM
Mandelbroth

3 
856 
I’m having a little trouble understanding why Green’s Theorem is defined as;
∮_C P dx+Q dy = ∬_D dA
Instead of;...

Dec1113 04:09 AM
TysonM8

2 
740 
How do I integrate:
\int\dfrac{dx}{(a^2sin^2(x)+b^2cos^2(x))^2}
Multiplying and dividing by sec^4(x) doesn't work,...

Dec1013 07:48 PM
Simon Bridge

4 
868 
I am confused with solving for horizontal asymptotes. I know you are supposed to find limits to positive and negative...

Dec1013 06:01 PM
genevievelily

3 
558 
Simple question;
http://i.imgur.com/gGj1NsO.jpg?2
Why isn't it \sum am (from m=1 to infinity)
Thanks in...

Dec1013 11:58 AM
jbunniii

1 
684 
does e^x*x^(t1)=
e^(t*ln(x)ln(x)x)
heres my reasoning:
x=e^ln(x)
e^x*x^(t1)=
e^x*e^(ln(x)(t1))=...

Dec1013 11:21 AM
HallsofIvy

3 
624 
I remember when I took Calculus B in college. I had never learned any math by reverse engineering before, but when I...

Dec1013 10:44 AM
HallsofIvy

1 
509 
\displaystyle\int_0^\pi\dfrac{x dx}{a^2sin^2(x)+b^2cos^2(x)}
I have to prove this to be equal to \dfrac{\pi^2}{2ab}...

Dec1013 06:56 AM
D H

1 
542 
y =f(x), and y'=df(x)/dx, F(y)=y^3+(y')^2
how to deal with the (y')^2 when i calculate dF(y)/dy?
thanks.

Dec913 01:48 PM
HallsofIvy

4 
717 
Does ##g(x,y,z)## (the equation of the surface) need positive z or negative z when doing a surface integral?
...

Dec913 01:46 PM
HallsofIvy

2 
600 
Hey, does anyone know of a proof that the sinc function
Si(x) = \int \frac{\sin x}{x} \, dx
is not elementary?...

Dec913 04:02 AM
jackmell

4 
722 
Hi, does anyone know if this function:
f(x) = \sum_{k=1}^\infty \frac{(1)^n}{x^{2k}}
is representable as an...

Dec713 07:55 PM
pierce15

4 
701 
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 
577 
http://i.imgur.com/rTf1iaC.png
If instead of evaluating the above line integral in counterclockwise direction, I...

Dec713 08:33 AM
vanhees71

7 
926 
I am trying to compute the determinant of the Jacobian matrix of
the ndimensional spherical coordinates.
i will...

Dec613 01:24 PM
hedipaldi

0 
557 
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 
701 
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 
652 
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 
715 
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 
802 
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 
694 
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 
498 
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 
634 
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 
548 
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 
411 
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 
842 
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 
761 
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 
592 
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 
762 
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 
834 
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 
563 
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 
481 
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 
607 
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 
632 
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 
649 