SL 2.1—Straight lines
- Syllabus
- First assessment 2021
- Objective
- —
- Level
- SL
Use gradient and intercepts to write a line
Use gradient and intercepts to write a line.
A line can be written y=mx+c; m measures change in y per unit x and c is the y-intercept.
Worked example
Through (1,3) and (3,7), m=2 and c=1, so y=2x+1.
Worked example
Are lines with equal gradients parallel? yes, unless they are the same line.
Common boundary
Perpendicular gradients are negative reciprocals, not simply opposite signs.