1. The problem statement, all variables and given/known data (phi)n (theta)=(2*pi)^(-1/2) * e^i*n(theta) 0<=theta<=2pi Show that the set of functions is orthonormal where n is an integer 2. Relevant equations (phi)n (theta)=(2*pi)^(-1/2) * e^i*n(theta) 0<=theta<=2pi Definition of orthonormal: functions are orthogonal and of unit length Definition of orthogonality: integral psi i* psi j dTau=0 3. The attempt at a solution At first i wasnt sure what it meant by unit length so i integrated the equation from 0 to 2pi i got (-i*e^i*n*theta)/((root(2pi)) * n) but i dont know how to evaluate to see if it is equal to 0. And if by unit length it means normalize, do i need to normalize the equation first then integrate and see if its equal to 0? thanks for any help in clearing this up. EDIT: btw how do people show their equations with nice symbols and such?