Extracting coefficients from an equation to set them to zero

Questions
1

Dear All,

(This is a math problem. Solving an equation)

I am trying to extract the coefficients in eq2 ( Derivative[1][[Psi]][[Xi]]/[Psi][[Xi]]) and then set them equal to zero.

But it’s not possible. Can you help me?

Open in Wolfram Cloud ↗
2

You can set the denominator to 1:

eq2 /. \[Psi][\[Xi]] :> 1
CoefficientList[%, \[Psi]'[\[Xi]]]
3

right on.

I very much appreciate your help.