Infinite potential well problem normalization

[Ashish Somwanshi]

Homework Statement

Suppose an electron in an infinite potential well with width, L, has a wavefunction,
ϕ(z)=Az(z−L) for 0<z<L
Normalize this wavefunction and derive an expression for the constant A in terms of L.

Relevant Equations

∫|ψ(x,t)|^2dx=1, integral lower bound: minus infinity
Upper bound: positive infinity

I have attached my attempt and proof that my attempts were incorrect.

 

[PeroK]

According to the homework guidelines you must make your best attempt at this before we can help.

 

[Ashish Somwanshi]

According to the homework guidelines you must make your best attempt at this before we can help.

 

[PeroK]

Your method is fine. Double check your final calculations- using $60$ as a common denominator, perhaps.

 

[Ashish Somwanshi]

Your method is fine. Double check your final calculations- using $60$ as a common denominator, perhaps.

Yeah, doesn't work. Please do provide your solution.

 

[Ashish Somwanshi]

Yeah, doesn't work. Plz do provide your solution.

 

[Ashish Somwanshi]

Yeah, doesn't work. Plz do provide your solution.

This is my final attempt despite using 60 as common denominator.

 

[topsquark]

This is my final attempt despite using 60 as common denominator.

Okay, let's try this again. $\dfrac{1}{5} - \dfrac{2}{4} + \dfrac{1}{3}$ is what?

-Dan

 

[Ashish Somwanshi]

Okay, let's try this again. $\dfrac{1}{5} - \dfrac{2}{4} + \dfrac{1}{3}$ is what?

-Dan

Sorry, I don't understand how to add three fractions using common denominator, in my first attempt I did the old way but still incorrect. Plz do provide the solution if anyone can solve their way. Either the autograder must be faulty or something I must be missing...

 

[Ashish Somwanshi]

Okay, let's try this again. $\dfrac{1}{5} - \dfrac{2}{4} + \dfrac{1}{3}$ is what?

-Dan

It's 1/12 according to evaluating two fractions one at a time.

 

[berkeman]

Plz do provide the solution if anyone can solve their way.

No, we do not provide solutions. You really don't understand how to add those fractions? Also, please do not use text speak at PF like "please". Thank you.

 

[Ashish Somwanshi]

I will redo the solution as I have made silly mistakes in evaluating the fractions...Thanks for spotting it.

 

[Ashish Somwanshi]

I will redo the solution as I have made silly mistakes in evaluating the fractions...Thanks for spotting it.

Guys, Thank you soo much. I've got a passing grade. It is mind boggling to see myself perform childish mistakes doing advanced quantum physics. I am currently analyzing reasons responsible for such performance.