No, its not. In a function, each x value has only one corresponding y value. In this relation, the x value 3 has corresponding values of both -1 and 5, which means it cant be a function.
Increased in occupational specialization in industrial field
It is africa hope this helps
This means "what benefits does the volcanic activity have for the population?" I would say that the main benefit of continental volcanic activity is the expulsion of ash which can enrich the soil and in the tropics make it good for growing coffee, for example, as it does in El Salvador.