Please help with the following question, thanks.

Suppose two operators 121 and 5' such that [121 3] a 0 but [121 [14,13]] 2 [13' [14,13]] (a) Prove that [151": B] = f(n)A\""1[x'iaI?] for some function f (n) of the integer n, and derive the function f (n) (b) Show that for any complex A we may write [ta/'4, B] = ABA4m, B]. (c) Derive the relation 8A+B = 8.4636[A131x2