Abandoned Caculus math class

Math - Calculus - Derivative. One day you are walking down the halls and you pass a class you never seen before, you decide to check it out. The bell doesn't ring for another 3 minutes. When you enter you realize that it is an old math class. You decide to check it out. You turn around and you see that the door has locked behind you. You try to check the handle and as you thought it was locked. You see a old janitors box of keys, but it is locked by 5 locks. You have to search the class for clues to find the answer to the locks...

Class Schedule

(Hint!!!!!!!!!!!!!!!!!!!!!!!) This is huge help------------------------------------------------------>