Slope of a line
Initial explanation
The slope of a line is a measure of how inclinated is a line.
The slope is always a rate of change. This means that it is a number that indicates how much a line change from point to point.
It is the rate of change of y axis and x axis:
m = Δy/Δx
Step 1: picking two points of the line
We are going to select two points of the given line:
We are going to determine the coordinates of both points:
The location of the first point is
(0, 60)
this is:
x₁ = 0, y₁ = 60
and for the second:
(5, 30)
this is:
x₂ = 5, y₂ = 30
Step 2: change of each variable
We want to see how much the line changed in the x axis from point 1 to point 2:
Δx = x₂ - x₁ = 5 - 0 = 5
and its change in the y axis is:
Δy = y₂ - y₁ = 30 - 60 = -30
Step 3: slope
Then, the slope is
Then, the slope is -6
Interpretation
As we said at the beginning, the slope represents how much a line changes.
In this case it shows as that its changes -6 each hour. Then, it decreases each hour.
This means that it is the percentage that Nolan's phone loses each hour.