Slope (Gradient) of a Straight Line
The Slope (also called Gradient) of a straight line shows how steep a straight line is.
The method to calculate the slope is:
So the slope is equal to 1
(The line is steeper, and so the slope is larger)
(The line is less steep, and so the slope is smaller)
Positive or Negative?
- Starting from the left end of the line 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 slope.)
(A line that goes straight across has a slope 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" line's slope 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