Stage 1 - Product rule:Originally Posted by Bert
Stage 2 - Chain rule on last term on the right:
From here you should be able to simplify this yourself.
I have here a strength differential
Normally is not a big problem but I making a mistake I don't know:
let my try thus
Now I need to multiply al the thinks and then I find but it's not correct.
Where do I miss ? Greets.