: Partial differential equations, Fourier series, Bessel equations, and Picard's existence theorem. Numerical Methods

Simultaneous linear differential equations and matrix methods.

: Differential Equations by Ralph Palmer Agnew is a highly regarded, classic textbook first published mid-century (with a notable second edition in 1960). It is famous for its clear, pedagogical, and sometimes humorous approach to ordinary differential equations.

It starts snowing in the morning and continues heavily and steadily throughout the day. A snow-plow starts plowing at noon and plows 2 miles in the first hour, and 1 mile in the second. What time did it start snowing?

Do not skip the introduction sections; Agnew lays the foundation well.

: The Internet Archive is a digital library that aims to provide free access to millions of books. It is the most likely place where a legally-digitized or borrowed copy of an out-of-print textbook like Agnew's might be found. Due to the nature of copyright law, access may be limited (e.g., borrowing for one hour at a time), but it remains a legitimate resource.