I'm beginning a directed study in QFT this fall and my supervising instructor told me I'd need to know some basics of Lagrangian and Hamiltonian Mechanics before we began (he also told me I needed to go back and review Perturbation Theory) since I'd need to know the formalism I guess? I've read through the first chapter of Goldstein and am working into the second chapter but he said the book might be "unnecessarily difficult" in places. He told me Ch 2 and Ch 7 from that book if I was going through it (well, he said Ch 8 but I think the libraries copy had a different edition). I know what a Lagrangian is and what a Hamiltonian is and a little bit about why Lagrangians are useful (how to get Newtonian equations from them etc) but nothing very deep. Do you have an recommendations if I just need a brief but strong overview of the classical equations used? Should I just focus on Lagrange's equations first or would it be reasonable to work on both sets simultaneously? He probably wouldn't mind covering it himself too much but I'd like to have a firm grasp of how to use them still, so if it's not possible in four weeks time I'd still like some recommendations. He uses the Taylor book for the class he teaches in Mechanics but he said he didn't want me to go out and buy a book if myself or the library didn't have it. I do have access to a number of other popular books though (we do have a decent library). I should give a little more specific background so you can direct me to appropriate resources. I'm an undergraduate Applied Math/Physics major at a small school and I've finished Calc I (Stewart-ish book), Calc II(Stewart-ish book), Calc III(Stewart-ish book), Differential Equations(Boyce and DiPrima) and Linear Algebra(Strang). I've completed Physics I-III(Haliday and Resnick) and have privately studied Quantum Mechanics(Griffith's Ch 1-5) with a professor at another university. I'm not very far along in Physics but he thinks we can work through the Ryder book with some effort. Thank you in advanced for your help and for your time!