Can you help me to explain how can i obtain this derrivative result?

[Icebear54]

Hi! I want to ask something. My friend asked me to help to check if the derrivative of equation 9 is shown by equation 10. I don't really how to solve it manually so I try to check from mathematica, but the result is different. Can you help me to check and explain if the derrivative in equation 10 is actually correct?

This is the mathematica syntax i use and the result :

 

[Dr.Peterson]

Hi! I want to ask something. My friend asked me to help to check if the derrivative of equation 9 is shown by equation 10. I don't really how to solve it manually so I try to check from mathematica, but the result is different. Can you help me to check and explain if the derrivative in equation 10 is actually correct?
View attachment 36886
This is the mathematica syntax i use and the result :
View attachment 36887

It doesn't claim to be a derivative, does it? It says it's [imath]\theta^*[/imath].

It looks like they are saying they took the derivative, set it to zero, and solved for [imath]\theta[/imath], which they are calling [imath]\theta^*[/imath].

I haven't tried to confirm their result, but you can probably do so with Mathematica.

 

[blamocur]

It looks like they are saying they took the derivative, set it to zero, and solved for θ\thetaθ, which they are calling θ∗\theta^*θ∗.

I haven't tried to confirm their result, but you can probably do so with Mathematica.

My quick-and-dirty script (with some random values for constants) seems to confirm your hypothesis.