Answer:
void distance(int x1, int x2, int y1, int y2){
pointsDistance = sqrt((x2-x1)^(2) + (y2-y1)^(2));
}
Explanation:
Suppose we have two points:


The distance between these points is:

So, for points (1.0, 2.0) and (1.0, 5.0)

I suppose this questions asks me to write a code, since i have to attribute the result to pointsDistance. I am going to write a C code for this, and you have to include the math.h library.
void distance(int x1, int x2, int y1, int y2){
pointsDistance = sqrt((x2-x1)^(2) + (y2-y1)^(2));
}