ODE introduction textbook

reference-request book-recommendation ordinary-differential-equations

I think these two are quite good:

Elementary Differential Equations with Boundary Value Problems (Edwards &Penney)

An Introduction to the Theory of Numbers (G Hardy)


For learning ODE's, a popular undergraduate book is

1.)Differential Equations with Boundary Value problems-Polking, Bogges, Arnold.

If you want to see many examples, I recommend you get the

2.)Schaum's Outline on Differential equations-Bronson,Costa.

From personal experience I highly recommend both of these books. If you want to see slightly more advance topics with a geometric taste I recommend

3.) Ordinary Differential Equations-V.I. Arnold

As for Number theory, if you want a computational approach, consider

1.) Elementary Number Theory-Burton

For a more theoretical approach,

2.) A classical Introduction to Modern Number theory-Rosen, Ireland 3.) Introduction to Analytic Number Theory-Apostol

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