This is for problem 2.5 in griffiths text(adsbygoogle = window.adsbygoogle || []).push({});

basically they say that the wave function as Capital Si (x,0) = A (si1(x) + si2(x), where si1 and si2 are equal to the first two stationary states of an infinite square well.

i need to get Cn..my normalization constant is sqrt(2)/2..and i'm using the same formula that they use to get it in example 2.2

so I use equation 2.37

Cn = sqrt (2/a) * int (sin (n*pi*x/a) * Si (x,0) dx, 0, a)

into this equation i insert (Sqrt(2)/2) * si (x,0) which was given in the initial question as

si (x,0) = A(si1(x) + si2(x)) where si1 and si2 are the solutions to the first two stationary states of the infinite square well

these should be si1 = sqrt (2/a) * sin (pi*x/a) and

si2 = sqrt (2/a) * sin (2*pi*x/a)

anyways, i'm wondering if I"m doing it write up to here..because in the next step i'm not sure how to simplify the equation to integrate easily so i just plug it into the calculator.

this gives me a function of n as is used in example 2.2 to get Cn...however, my equation has sin n*pi multiplied by the rest of the equation..the problem is that sin n*pi is always equal to zero for any integer n. Therefore i have no Cn.

Obviously i'm doing something major wrong. So i was hoping to get some help on this. I've solved problem 36 ok since it doesn't require much.

2.6 i haven't really tried yet since squaring the initial wave function looks like a beast since it looks like a pain to square (assuming you turn e^itheta into cos theta + isin theta), though i will get to it soon hoepfully..

2.37 i also tried though..and normalizing it was ok (sqrt(16/5)), but i again was unable to get Cn..my calculator when giving the integral solution again leaves me with sin npi as a major factor..so i wonder if i'm plugging things in wrong.

Anyways, getting Cn is a major factor in these problems so i could really use some help:\

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# Homework Help: Calculating Cn for general wave solutionbasic Quantum physics

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