Differential equations occur throughout physics and being able to solve them is a critical mathematical skill for physicists. The first part of the course emphasizes solution techniques to first-order and linear, second-order ordinary differential equations, including series and Frobenius solutions, and an introduction to Fourier and orthogonal series and Sturm-Liouville problems. The second part of the course introduces partial differential equations with a study of quasilinear first-order equations, and the linear second-order wave, heat and Laplace equations, and solution techniques including the method of characteristics and separation of variables. Examples from physics will be emphasized throughout. Prerequisite: MATH 146 or equivalent and one of MATH 102 or 125 or 127. Corequisite: MATH 214 or 217. Note: Credit may be obtained for only one of MA PH 251, MATH 201, MATH 334 or MATH 336.