All HiSET: Math Resources
Example Questions
Example Question #1 : Use The Zeros To Construct A Rough Graph Of A Function
Which of the functions below best matches the graphed function?
First, look at the zeroes of the graph. Zeroes are where the function touches the x-axis (i.e. values of where ).
The graph shows the function touching the x-axis when , , and at a value in between 1.5 and 2.
Notice all of the possible answers are already factored. Therefore, look for one with a factor of (which will make when ), a factor of to make when , and a factor which will make when is at a value between 1.5 and 2.
This function fills the criteria; it has an and an factor. Additionally, the third factor, , will result in when , which fits the image. It also does not have any extra zeroes that would contradict the graph.
Example Question #1 : Rate Of Change Of A Function
What is the slope of the line given by the following table?
Given two points
and
the formula for a slope is
.
Thus, since our given table is
we select two points, say
and
and use the slope formula to compute the slop.
Thus,
.
Hence, the slope of the line generated by the table is
.
Example Question #1 : Rate Of Change Of A Function
Define .
Give the average rate of change of over the interval .
The average rate of change of a function over an interval is equal to
Setting , this is
Evaluate and by substitution:
,
the correct response.
Example Question #1 : Calculate And Interpret Rate Of Change Over A Specified Interval
Define .
Give the average rate of change of over the interval .
The average rate of change of a function over an interval is equal to
Setting , this is
Evaluate using the definition of for :
Evaluate using the definition of for :
The average rate of change is therefore
.
Example Question #1 : Estimate Rate Of Change From A Graph
The graph of a function is given above, with the coordinates of two points on the curve shown. Use the coordinates given to approximate the rate of change of the function between the two points.
The rate of change between two points on a curve can be approximated by calculating the change between two points.
Let be the coordinates of the first point and be the coordinates of the second point. Then the formula giving approximate rate of change is:
Notice that the numerator is the overall change in y, and the denominator is the overall change in x.
The calculation for the problem proceeds as follows:
Let be the first point and be the second point. Substitute in the values from these coordinates:
Subtract to get the final answer:
Note that it does not matter which you assign to be the first point and which you assign to be the second, as it will lead to the same value due to negatives canceling out.
Example Question #1 : Estimate Rate Of Change From A Graph
Above is the graph of a function . Estimate the rate of change of on the interval
The rate of change of a function on the interval is equal to
.
Set . Refer to the graph of the function below:
The graph passes through and .
. Thus,
,
the correct response.
Example Question #3 : Rate Of Change Of A Function
Above is the graph of a function , which is defined and continuous on . The average rate of change of on the interval is 4. Estimate .
The rate of change of a function on the interval is equal to
.
Set . Examine the figure below:
The graph passes through the point , so . Therefore,
and, substituting,
Solve for using algebra:
,
the correct response.
Example Question #1 : Estimate Rate Of Change From A Graph
Above is the graph of a function. The average rate of change of over the interval is . Which of these values comes closest to being a possible value of ?
The average rate of change of a function on the interval is equal to
.
Restated, it is the slope of the line that passes through and .
To find the correct value of that answers this question, it suffices to examine the line with slope through and find the point among those given that is closest to the line. This line falls 4 units for every 5 horizontal units, so the line looks like this:
The -coordinate of the point of intersection is closer to 2 than to any other of the values in the other four choices. This makes 2 the correct choice.
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