Show by examining the position of the nodes that Re[A + e i(kx t) ] and Re[A

Show by examining the position of the nodes that Re[A₊e ^{i(kx−ω t)} ] and Re[A_–e ^{i(−kx−ω t)} ] represent plane waves moving in the positive and negative x directions, respectively. The notation Re [ ] refers to the real part of the function in the brackets.