### Author Topic: S2.4 online textbook  (Read 1051 times)

#### Yan Zhou

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##### S2.4 online textbook
« on: January 20, 2020, 06:33:20 PM »
Does anyone know why is there a -1/4 in the middle equation in picture 1?
From section 2.3, we have the equation on the second picture.
So I think it is a typo. If it is not, please let me know! Thanks in advance.
PS: Does anyone know how to use latex in the post?