Thread: commutators

[x, i d/dx] what is the value of this commutator
can anyone check my work please:

[x, i d/dx] = ixf '(x) - if (x) - ixf '(x)

[x, i d/dx] f(x) = -if(x)

[x, i d/dx] = -i

Originally Posted by myoplex11

[x, i d/dx] what is the value of this commutator
can anyone check my work please:

[x, i d/dx] f(x) = ixf '(x) - if (x) - ixf '(x) Mr F says: The red f(x) needs to be included.

[x, i d/dx] f(x) = -if(x)

[x, i d/dx] = -i

Looks fine.