Mathematics · Ch 5 — Straight Line
Straight Line
Straight Line
5.2 Straight Line
A straight line is the simplest possible locus in a plane: its defining characteristic is that the slope of the segment joining any two points on it is always the same constant value.
If a line meets the X-axis at , then is called the X-intercept of the line. If it meets the Y-axis at , then is called the Y-intercept.
Remarks.
- A line parallel to the X-axis never meets the X-axis, so it has no X-intercept.
- A line parallel to the Y-axis never meets the Y-axis, so it has no Y-intercept. …
What this figure shows. Diagram showing a line crossing the X-axis at A(a,0) and the Y-axis at B(0,b), illustrating the X-intercept a and Y-intercept b. This figure gives the reader a concrete visual reference for the geometric configuration described in the surrounding text, tying the abstract statement t …
Worked out. Notes that a line parallel to the X-axis has no X-intercept and a line parallel to the Y-axis has no Y-intercept, then poses two thinking questions: can an intercept be zero, and can it be negative? …