All Precalculus Resources
Example Questions
Example Question #1 : Derivatives
Find the average rate of change of the function over the interval from to .
The average rate of change will be found by .
Here, , and .
Now, we have .
Example Question #2 : Derivatives
Let a function be defined by .
Find the average rate of change of the function over .
We use the average rate of change formula, which gives us .
Now , and .
Therefore, the answer becomes .
Example Question #2 : Rate Of Change Problems
Suppose we can model the profit, , in dollars from selling items with the equation .
Find the average rate of change of the profit from to .
We need to apply the formula for the average rate of change to our profit equation. Thus we find the average rate of change is .
Since , and , we find that the average rate of change is .
Example Question #3 : Rate Of Change Problems
Let the profit, , (in thousands of dollars) earned from producing items be found by .
Find the average rate of change in profit when production increases from 4 items to 5 items.
Since , we see that this equals. Now let's examine . which simplifies to .
Therefore the average rate of change formula gives us .
Example Question #5 : Derivatives
Suppose that a customer purchases dog treats based on the sale price , where , where .
Find the average rate of change in demand when the price increases from $2 per treat to $3 per treat.
Thus the average rate of change formula yields .
This implies that the demand drops as the price increases.
Example Question #6 : Derivatives
A college freshman invests $100 in a savings account that pays 5% interest compounded continuously. Thus, the amount saved after years can be calculated by .
Find the average rate of change of the amount in the account between and , the year the student expects to graduate.
.
.
Hence, the average rate of change formula gives us .
Example Question #1 : Rate Of Change Problems
Find the average rate of change of between and .
The solution will be found by the formula .
Here gives us , and .
Thus, we find that the average rate of change is .
Example Question #1 : Rate Of Change Problems
Find the average rate of change of over the interval from to .
The average rate of change will be .
.
.
This gives us .
Example Question #2 : Rate Of Change Problems
Find the average rate of change of over the interval from to .
The average rate of change will be .
Now.
We also know .
So we have .
Example Question #2 : Rate Of Change Problems
Why can we make an educated guess that the average rate of change of , between and would be ?
We know is vertical on that interval.
We know is symmetrical on that interval.
We know is horizontal on that interval.
We know is odd on that interval.
We know is a polynomial.
We know is symmetrical on that interval.
Because is symmetrical over the y axis, it increases exactly as much as it decreases on the interval from to . Thus the average rate of change on that interval will be .