# Mistake answer model lecture 14 Exercise 4.4

**URL:** https://forum.solidstate.quantumtinkerer.tudelft.nl/t/mistake-answer-model-lecture-14-exercise-4-4/1814
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**Created:** [March 30, 2022, 8:16pm UTC](https://forum.solidstate.quantumtinkerer.tudelft.nl/t/mistake-answer-model-lecture-14-exercise-4-4/1814 "2022-03-30T20:16:10Z")
**Posts on this page:** 2
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### Author: ![rmwesterveld](https://forum.solidstate.quantumtinkerer.tudelft.nl/letter_avatar_proxy/v4/letter/r/ba9def/32.png) [@rmwesterveld](https://forum.solidstate.quantumtinkerer.tudelft.nl/u/rmwesterveld)
#### Post date: [March 30, 2022, 8:16pm UTC](https://forum.solidstate.quantumtinkerer.tudelft.nl/t/mistake-answer-model-lecture-14-exercise-4-4/1814/1 "2022-03-30T20:16:10Z")

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Hi, I think I found another mistake, namely with the density of states for both electrons and holes. I think a for factor \frac{L\_x L\_y}{(2 \pi)^2} is missing since this always comes in front of the density iof states.

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### Author: ![RensOlsthoorn](https://forum.solidstate.quantumtinkerer.tudelft.nl/letter_avatar_proxy/v4/letter/r/71c47a/32.png) [@RensOlsthoorn](https://forum.solidstate.quantumtinkerer.tudelft.nl/u/RensOlsthoorn)
#### Post date: [March 31, 2022, 11:43am UTC](https://forum.solidstate.quantumtinkerer.tudelft.nl/t/mistake-answer-model-lecture-14-exercise-4-4/1814/2 "2022-03-31T11:43:22Z")

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No, the \hbar should be h in the answers.