Missing 'x' in Expectation Value Formula

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SUMMARY

The expectation value formula in quantum mechanics is correctly expressed as = <\psi|x|\psi> = \int_{-\infty}^{\infty}\psi^*x\psi dx. The original formula presented in the textbook, = \int \Psi^{*}\Psi dx, is incomplete as it lacks the necessary 'x' operator next to |\Psi|^{2}. This omission can lead to errors when applying other operators, such as momentum (p), in calculations.

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Void123
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Homework Statement



In my textbook, the formula for the expectation value is written as:

&lt;x&gt; = \int \Psi^{*}\Psi dx

Shouldn't there be an x next to |\Psi|^{2} ?

Thanks.



Homework Equations





The Attempt at a Solution

 
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yes it should read&lt;x&gt;=&lt;\psi|x|\psi&gt; = \int_{-\infty}^{\infty}\psi^*x\psi dx

make sure you write it in this form too. Otherwise when you start putting in other operators like p you will get it wrong.
 

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