physical chemistry

Problem 3 Operators play an important part in quantum mechanics. An operator (x) can be any mathematical operation that is performed onto a function f(x). When the operation (x)f(x) produces a constant c times the function f(x), i.e. (x)f(x)=cf(x), then the function is said to be an eigenfunction of (x). Determine whether the following functions are eigenfunctions of the operator (x)=d2/dx2 : a) f(x)=eiax b) f(x)=eax2 c) f(x)=x2 d) f(x)=acos(bx) c) f(x)=xeax