If f = 0 for any point, then the two lines touch at a point. If f1_1 and f1_2 are equal or f2_1 and f2_2 are equal, then the lines do not intersect. If f1_1 and f1_2 are unequal and f2_1 and f2_2 are unequal, then the line segments intersect.

What is it called when two line segments intersect?

In geometry, an intersection is a point, line, or curve common to two or more objects (such as lines, curves, planes, and surfaces). The simplest case in Euclidean geometry is the intersection of two distinct lines, which either is one point or does not exist if the lines are parallel.

Do two lines always intersect?

Parallel & Intersecting lines Two lines in the same plane will always intersect unless they are parallel. ... An intersection point can have infinitely many lines going through it, however two lines can only intersect at one point.