hello all, i'm an EE student,and i've recently started studying quantum mechanics. most text books start with schrodinger's equation directly but a few others (like say Liboff) start with the concept of hamiltonian from hamiltonian mechanics. is a knowledge of the same i.e hamiltonian/lagrangian mechanics essential for a thorough study of QM? if yes, could someone suggest a good, easy-to-understand text for the former? i tried referring a few books but they require knowledge of variational calculus. (i kinda feel the whole process frustrating, spending so much time on this chain of one book to other, ending up doing very little useful work) thanks.