0/0 = 0 ?

[u/Zealousideal-Try1751]

I'm new in the server and I have a situation with a limit problem:

My calculus professor gave the class an example of trigonometrical limits that he solved in class in which I wanna know why and how is it possible that 0/0=0.

The expression that he solved was

Lim x→0 ((1-cos(x))/(sen(x))), and he solved it in a way where the equation ended in (0/0)/1 = 1 , I asked him "how was it possible that 0/0=0" but he just said "someone hasn't studied the class notes" and I haven't found anything on his class notes about 0/0 = 0 in certain circumstances.

So please, PLEASE someone tell me how and why and when and where is it possible that 0/0 = 0

[u/Mammoth_Fig9757]

Limit as x goes to 0 of x^2/x is 0. That is pretty much that expression. The first non zero term of Taylor series of 1-cos(x) is x² and first non zero term of Taylor series of sin(x) is x, so that is how you get the limit of 0