# Integrate This

1. Dec 29, 2005

### samalkhaiat

Happy new year for you all,
This is very nice place, So girls and boys, let me give you something to play with:
Integrate (r^.a)(r^.b)(r^.c)(r^.d) d(cos8)
from cos8=1 to cos8=-1.
a,b,c and d are constant vectors, r^ is the unit vector
(iX+jY+kZ)/|r|, 8 is the spherical angle between r^ and Z-axis.
The dot represents the scalar product.
When you have done that, do this one:

(a.r^)/(1+K.r^) d(cos8)
the limits of integration same as befor, a and K are constant vectors.

cheers

sam

2. Dec 29, 2005

### abdo375

plzzzzzzzzzzzzzzzzzzzzz take sometime and learn latex

3. Dec 29, 2005

### Tom Mattson

Staff Emeritus
:rofl: :rofl:

I have to agree, I can't really tell what's supposed to be going on there with the carets. And integrating with respect to the number 8? Is that really what you meant?

4. Dec 30, 2005

### Lisa!

I've not noticed we could use $$8$$ instead of $$\theta$$ !

Last edited: Dec 30, 2005
5. Dec 30, 2005

### Tide

$$\frac {2}{5} a b c d$$

I was tempted to say 0 because 8 is usually a constant so that d cos(8) = 0. ;)

6. Dec 30, 2005

### samalkhaiat

[
[/QUOTE]

1) I don't have that "sometime".
2) It is to complicated for my little brain.

sam

7. Dec 30, 2005

### fargoth

1) I don't have that "sometime".
2) It is to complicated for my little brain.
sam[/QUOTE]

just click on the equations and see how they wrote it... im sure youd figure it out...

8. Dec 30, 2005

### Pengwuino

Find time :)

And if you can integrate, i don't think its too complicated for you... especially with a program such as texaide

9. Dec 30, 2005

### samalkhaiat

[
The carets used to distinguish between a vector and its "unit vector":rofl::rofl:
[/QUOTE]
No. The 8 , as I said, is the spherical angle(do you remember theta), it is just a symbol:tongue2: :tongue2:

sam

10. Dec 30, 2005

### samalkhaiat

Yes darling, you could if you think of 8 as symbol.:zzz:

sam

11. Dec 30, 2005

### samalkhaiat

Yes, now this answer is write, if 8 was a number, but it is not. So,even your temptation is wrong.:tongue2: :rofl:

good luck

sam

12. Dec 30, 2005

### Tide

samal,

Prove it! :)

13. Dec 30, 2005

### samalkhaiat

14. Dec 30, 2005

### fargoth

the final answer has mixed parts of a b c and d in it, not only $$a_xb_x$$ etc. so it cant be abcd

15. Dec 30, 2005

### fargoth

16. Dec 30, 2005

### samalkhaiat

Last edited: Dec 30, 2005
17. Dec 30, 2005

### samalkhaiat

18. Dec 30, 2005

### samalkhaiat

19. Dec 31, 2005

### Lisa!

I meant I hadn't noticed te similarity, dear!

20. Dec 31, 2005