Woops. Was this the only problem? I think this only changes the arctg from the final answer and not the ln(..) of the answer. I hate when this type of error happens..
Hello everyone
I have an exam tomorrow and I would really appreciate if someone could tell me what I did wrong with this exercice. I did it on paper and I scanned it. Here is the link to the scan:
The answer in the book is sqrt(x^2 + x +5/4) + 2ln(sqrt(x^2 + 2x + 2) + x +1) + C...
Thanks for your help, Daniel.
I see my solution was okay. We had to do the problem by exponents of sec and tg. (sorry I dont know what the method is called in english)
However, what does d(cos u) means in your solution? and I know you replaced a sin^4 (u) by (1-cos^2 (u)), but where is the...
I have this integration problem that I did but it doesnt give me the right answer. But there are like 3 other similar exercices I did the same way and I got all the right answers.. maybe it is my book (I dont think so ... :p)
It's an integration problem:
\int tg^3(4x) sec^4(4x)dx
heres...
Hello everyone.
I have been trying to do those 2 exercices for a while now and I can't get it.. We just started doing Integration by parts (is that how you call it in english?)
here are the problems
1) \int{ (x^3)(e^{x^2})}
and
2) \int{ \frac{{(x)(e^x)}} { (x+1)^2}}
for the 2nd...
Hello, I have two questions concerning limits
1) lim x-> 0+ x^(sinx)
2) lim x-> +inf. (9^x)/(8^x)
The first one gives me 1 (e^0 = 1) .. is that correct?
The 2nd one I dont know how to do. Can someone please explain the 2nd one for me?
Thanks a lot
EDITED THE EQUATION
Hello all,
I have this problem I can't solve.. it is a infinite - infinite. I tried it around 5 times and can't find the correct answer (infinite). I'm pretty sure I have to put in evidence x^2 and use a limit law but I can't find the answer.. can someone help me for...
If by substitution you mean posing u=.. then replacing it, yes, we saw this in class.
I think I'll do what you said, since it seems like the only method (doing them in the scalar form). I tried to do them this way so I didnt have to take in account that it was positive/negative.
Thanks a lot...
Hello all, and sorry for making all those threads :shy:
I just want to know if I can do this (especially the last part)
\int{} \frac{-k\ \lambda \ dx \ x \vec{i} + 2\ k\ \lambda \dx \ \vec{j}}{(x^2 +4)^{3/2}}
= \int{} \frac{-k\lambda (x \vec{i} - 2\vec{j}) \ dx}{(x^2 +4)^{3/2}}...
Hello, I just wanted to know if you can integrate a vector, and if so, how.
Here is a problem: A charged piece of metal of linear density 2 * 10^-6 * x , between x=2 and x=5.
I found its charge by integrating.. and it is 21 micro C.
Now that's what I want to know: calculate the electric...
When I solve for x and y , I get x= (+-) 3,16 and y= 1,27 ...
Anyway, I already understood your first method, it's a lot more easier.. but I dont know why it never works like you have written.
Thanks a lot for all your time and help, Healey01 :)
Thanks a lot Healey01, I understand . :cool:
What I don't get is the teacher told me to equal the i and j vectors so it makes two different equations, and since I have 2 unknown values, I'd find them like that. Do you have any idea how to do that?
I tried
( 0,222 \vec{i} + 0,250\vec{j})...
That is the right answer, except it's (-1,8 i - 2,05j) (no problem there)
I just want to know from where comes the 0,3343(0,66399\vec{i} + 0,7477\vec{j}) = 0,3343\vec{u_{21}}
Thanks a lot for the help, can you just clarify this for me? :)
I still haven't received an answer for this one :P . I'll check tomorrow with my teacher. I'm in my 2nd session, and my cote R from the first one is great, so if I can continue like that, maybe next year I can make an admission. :) Thanks bro
Sorry for the question, I posted the one they asked but forgot to add that they're ponctual charges. It's in french, that's why I translated it. But basically, the two charges create a resultant force of the one I wrote in my post. They then ask where to put a ponctual 2,5Q charge to nullfy the...
I have been using vectors with units for over a year in my physics courses. Every teacher in the physics department teaches this. A force has components in i, j and k.. how can it not have units? But I dont want to start an argument here about this, that's what we use here. Thanks for pointing...
A force has a unit, Newtons, that's why I posted the N.It has a force in a direction i and j.
Healey01, thanks for the help but that's not the answer.
The question was there's two charge that create a force (the first one I posted) on another charge. They then add a 2,5Q charge and ask...
Hello, I have a simple exercice I'm having trouble to solve.
So we have a) and b)
a) asked the force applied on a charge.... and the answer was \vec{F_{res}.}= Qkq ( -0,222 \vec{i} -0,250\vec{j}) N
that's not a problem here.. that was the good answer. Now in b), they're asking where...