Chapter 3 Exercise 34, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

*3.34 (Geometry: point on line segment) Programming Exercise 3.32 shows how to test whether a point is on an unbounded line. Revise Programming Exercise 3.32 to test whether a point is on a line segment. Write a program that prompts the user to enter the three points for p0, p1, and p2 and displays whether p2 is on the line segment from p0 to p1. Here are some sample runs: Enter three points for p0, p1, and p2: 1 1 2.5 2.5 1.5 1.5 (1.5, 1.5) is on the line segment from (1.0, 1.0) to (2.5, 2.5) Enter three points for p0, p1, and p2: 1 1 2 2 3.5 3.5 (3.5, 3.5) is not on the line segment from (1.0, 1.0) to (2.0, 2.0)

// checking if the point is in range if (((x2 < x1 && x2 > x0) || (x2 < x0 && x2 > x1)) && ((y2 < y1 && y2 > y0) || (y2 < y0 && y2 > y1))) { double c = (x1 - x0) * (y2 - y0) - (x2 - x0) * (y1 - y0); if (c == 0) { s = " "; } } 

Could someone please explain to me the above lines of code? What is a discrimant? Why is the discriminant being used on this example? Is there another way to solve this problem without using boolean?