/sci/ - Science & Math

[Anonymous No.5027740]

Hey /sci/, I need help with part of this simple quantum mechanics problem. I have a wave function, psi, for a free particle and I'm calculating the probability that the particle's linear momentum results in a certain value. I can calculate the probability, but in order to do that I need to multiply the wave function by its complex conjugate, and I'm not sure what that is.

This is my wave function: http://www.wolframalpha.com/input/?i=sqrt%283%29%2F2e^%28ikx%29%2B1%2F2e^%28-ikx%29

For this problem, the professor wants each step in terms of e, not sin or cos. This is why I'm not sure whether I need to flip the sign of exponent of the real portion of the equation in addition to the unreal portion, or just to the unreal portion. Help would be much appreciated.

[Carl No.5027760]

>>5027740
replace i with -i.
http://www.wolframalpha.com/input/?i=complex+conjugate+of+sqrt%283%29%2F2e^%28ikx%29%2B1%2F2e^%28-ik
x%29

[Anonymous No.5027765]

>>5027760

Well, fuck me. For some reason I thought wolfram didn't perform that function. I guess you change the signs of both parts. Thanks.

[Anonymous No.5027767]

You're doing QM and you don't know what a complex conjugate is? Way to fail.

[sage No.5027770]

>doing QM
>can't do high school algebra
OP is an insane and mad idiot shit eater

[Anonymous No.5027773]

>>5027770
>putting sage in the name field

Newfag detected.

[Anonymous No.5027776]

>>5027767

I've never had to perform one on a function like that, all knowing one.

[Anonymous No.5027781]

>>5027776
How retarded are you? Complex numbers are highschool math.

[Anonymous No.5027789]

>>5027781

And I haven't done them since highschool.

[Anonymous No.5027790]

>>5027789
That's no excuse. What you're doing is like forgetting how to calculate 1+1. You're retarded.

[Anonymous No.5027791]

>>5027790

lol. Whatever you say, buddy.

[Anonymous No.5027801]

>>5027791
How is he wrong?

[Anonymous No.5027833]

>>5027790

Fucking elitist faggots.

Please post a link to your published dissertation, all-knowing faggot

[Anonymous No.5027837]

I think the chance of it resulting in a certain value between a and b is given by <span class="math">\int_a^b \psi^{*}h\space\psi\space dx[/spoiler] where h is the momentum operator.

[Anonymous No.5027839]

>>5027837

<span class="math">\int_a^b \psi^{*}h\psi dx[/spoiler]

[Anonymous No.5027845]

>>5027833
>he thinks complex numbers are PhD level

It's highschool shit. How much do you want to embarrass yoursefl?

[Anonymous No.5027852]

I think the momentum operator is <span class="math">ih \frac{d}{dx}[/spoiler]

[Anonymous No.5027857]

>>5027833

He is right, doing a QM course without knowing complex numbers is retarded

[Anonymous No.5027864]

I think the point that that guy (or those people, cant tell if all samefagging) is trying to make is that you should step your game up OP, youre in QM and if it's at all relevant to your major (which I'm assuming is Physics) then you should be able to manipulate complex conjugates. hell you should probably have a grasp on adjoint operators for that matter, but thats a different story.

[Anonymous No.5028056]

OP here again. I realize, as you all have so kindly pointed out, that I should have instantly known to flip the signs on both parts of the function for the conjugate, and not just on the unreal part. I give no fucks whether or not you think I should be in QM, and I think it's funny how some of you felt so badly like you needed to scold me. I've achieved nothing but A's thus far into college, so y'all niggers can suck up on this flaccid retard dick. haters gonna hate

[Anonymous No.5028092]

About all I was taught in high school about complex number was that i^2 was -1 and i^4 was 1. They told use we'd learn the rest later.

I figured there was some kind of complex number theory course I'd be required to take. Guess I'm wrong. Will I be prepared for QM when I take it?