Gradient (Slope) of a Straight Line
The Gradient (also called Slope) of a straight line shows how steep a straight line is.
The method to calculate the Gradient is:
So the Gradient is equal to 1
The line is steeper, and so the Gradient is larger.
The line is less steep, and so the Gradient is smaller.
Positive or Negative?
- Starting from the left end of the line and going across to the right is positive
(but going across to the left is negative).
- Up is positive, and down is negative
That line goes down as you move along, so it has a negative Gradient.
A line that goes straight across (Horizontal) has a Gradient of zero.
Straight Up and Down
That last one is a bit tricky ... you can't divide by zero,
so a "straight up and down" (Vertical) line's Gradient is "undefined".
Rise and Run
Sometimes the horizontal change is called "run", and the vertical change is called "rise" or "fall":
They are just different words, none of the calculations change.