Homework Statement:
below
Relevant Equations:
below
I'm just trying to follow the below

And I understand all, I think, except what's happened to the term when A hits 1: [A,1] ?
If I'm correct basically we're just hitting on the first operator so reducing the power by one each time of the operator in the right hand bracket

thanks

tnich
Homework Helper
If I understand this correctly, ##1## is the identity operator. So what would be the value of ##[A,1]##?

[A,1]=0 since 1 is pure number!

[A,1]=0 since 1 is pure number!
omg i think i need some sleeep ! thank you haha :)

omg i think i need some sleeep ! thank you haha :)
A typo! 1 here refers to identity operator as @tnich says. Anyways,final result is same