PHYS201x follows introductory physics courses with a more detailed treatment of oscillators, waves on strings, and electromagnetic waves. In addition to deriving and solving the wave equation, mathematical methods will be introduced on making approximations, describing oscillations with complex numbers, and synthesizing functions with Fourier series. Optical reflection and refraction will be derived, as well as the lens equation and elements of geometrical optics. Optical interference, diffraction, and polarization will be covered in detail, including the role of diffraction in image formation. PHYS201x will have weekly video lectures that explain the material through detailed derivations and demonstrations. There will be weekly homework, a discussion forum, and two exams. Eight weeks of content will be presented, and one week devoted to each self-paced exam.