Help with funcions

I am currently doing a work but I am confused and I am not succeeding. I'm a beginner in c. I need to start from another part of a program that will later be added to summarize a continuous component
I'm given this line of code already (void add_component_continuous (void add_component_continuous (float wave [], int size, float cc)) I don't know how to do it ... Because "wave" is a vector of variable size and I need to add to this vector to that component .. and in this line of code that is given to me "size" means the size of the vector i think e so I don't know if I will have to work with the size of the vector that I don't even understand why.
I'm currently desperate because I can't do it

hope anyone can waste a litle bit of time helping me

Also here -> Help With Functions - C And C++ | Dream.In.Code