Whwn i am doing exercise, i dont know how to solve the follow question by myself Although i hv the ans, i want to complete it by myself. Plz give me some tips only so that i can finish this question, please also tell me how do you know the question should be solved in this way. The question requires me to solve the wave equation for a pacticle in a infinity potential well, from x=-l/4 to x= 3l/4 I let the wave equ be the form Asinkx + B cos kx and i got. Asin(-kl/4) + B cos (-kl/4) = 0 and Asin(3kl/4) + Bcos(-3kl/4) = 0 and than i cant do anymore it is different from to x=0 to x= a case What should i do? Any tips? Is there any general solution for the wave fuction of the pacticle in a box from a point x to y?