# Do i need differential equations?

A friend recently gave me a book on quantum mechanics. It's called Introduction to quantum mechanics. It's by David j griffiths.

I am currently taking multivariable calc.I am taking linear algebra next semester.

I want study this book, but I am wondering what mathi I need. My friend told me I need diff eq, but can you please tell me what kind of math I need to do the stuff in the book.

I want to really be able to do everything in the book, what is the minimum ma99th that I need?, and what is the recommended(extra courses than bare minimum that could signifantly help)?

I can't imagine trying to solve any physical problems without differential equations. Granted, I'm a mechanical engineer and I deal with classical physics mostly, but I've had a quick intro to quantum and it's all full of partial differentials and things. You'll probably need classes on both ODEs and PDEs to solve any worthwhile quantum problems.

You'll need to know linear algebra, single/multi variable calculus, and how to solve some basic ordinary and partial differential equations. Courses in these fields can help, but are not necessary. Most physics programs require students to take a class that covers the mathematical techniques you'll need in undergraduate physics. These usually use a textbook such as Mathematical Methods for the Physical Sciences by Boas.

jtbell
Mentor
I am wondering what math I need. My friend told me I need diff eq,

Griffiths himself says, in the preface to the first edition (I don't know if he's changed this in the second edition):

Griffiths said:
The reader must be familiar with the rudiments of linear algebra, complex numbers, and calculus up through partial deriviatives [...]

He doesn't include differential equations in this list. Why not, when the Schrödinger equation is obviously a partial differential equation? In a introductory QM course we don't use the systematic methods of solving different types of DEs that one learns in a DE course; instead we teach simplified "cut and try" methods that work well enough for our purposes, because the DEs that we actually have to solve, once we've separated the variables, can pretty much be solved by inspection and a little guesswork and generalization. Take a look at the chapter on the time-independent Schrödinger equation (chapter 2 in the first edition) and see for yourself. He pretty much walks you through the process for the infinite square well.