0
$\begingroup$

Enter image description here

I've got this question to answer and from what I can tell, I need to take the square of the absolute value for the probability amplitude.

In this case I think the answer should be the square of $e^{i\phi} \cos(\theta)$

When I try to input this answer it returns "Phi is not a valid variable for this solution"

How do I go about tackling this question?

$\endgroup$
  • 2
    $\begingroup$ you seem to have forgotten to use the "absolute value" part that you mentioned. $\endgroup$ – DaftWullie Mar 25 at 15:55
2
$\begingroup$

Your question has most of the components of the answer: indeed you need to take the square of the absolute value for the probability amplitude.

You have to remember that $\cos \theta$ is a real number, and its absolute value is just $|\cos \theta|$, but $e^{i\phi}$ is a complex number (Euler's formula: $e^{i\phi}=\cos \phi + i \sin \phi$), so its absolute value is 1. The answer will be just $\cos^2 \theta$.

|improve this answer|||||
$\endgroup$
  • $\begingroup$ Thank you so much, I was definitely over thinking the question :) This field of maths is totally new to me, never used imaginary numbers. Just wanted to learn about nuclear power and they threw a quantum mechanics module at me lol Thanks again $\endgroup$ – Dominic Adams Mar 25 at 18:04

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.