Example
When you woke up, you notice that your tablet battery was charged at 94%. After 8 hours, your tablet battery was at 65%.
a) Find the rate of change (slope) of the battery percentage (including the units) and explain what it means in the context of this problem.
b) Write a linear equation in slope-intercept form for the battery percent, B, after , h, hours.
c) Using the equation above, find the h-intercept, including units. Explain what this means in the context of the problem.
Solution
By using this formula we can tell that the battery decreases 3.625% per hour
c) We use the formula that we just created to find out how long would the battery last.
After 25 hours and 54 minutes, the battery will die.
Equation, Table, and Graph
Reflection
This example is about the amount of finding out how long the battery will last by using rate of change and slope-intercept form. The problem performs the basic negative slope, but we have to define a slope first. The slope of a line is the steepness of the line. There are many ways to think about slope. Slope is the rise over the run, the change in 'y' over the change in 'x', or the gradient of a line. For a negative slope the y value decreases as the x value increases. For the example, as the day goes on the battery decreases. From 94% at zero hours to 65% in eight hours. This problem is at medium difficultly for ones that are not knowledgeable about slopes. Two equations are generally used for negative slopes. One being the rate of change and the other being slope-intercept form. The graph is displayed as a declining slope such as the problem as is ensued. This is a good start for intermediate algebra more so as not being too difficult, but not being too easy as well. It has the right amount to difficulty to learn the properties to move on to more difficult problems involving slope.