All HiSET: Math Resources
Example Questions
Example Question #1 : Identification
The equation
has two distinct solutions. What is their sum?
It is not necessary to actually find the solutions to a quadratic equation to determine the sum of its solutions.
First, get the equation in standard form
by subtracting from both sides:
If a quadratic equation has two distinct solutions, which we are given here, their sum is the linear coefficient
. In this problem, , making the correct choice.Example Question #271 : Hi Set: High School Equivalency Test: Math
The graph of the polynomial function
has one and only one zero on the interval
. On which subinterval is it located?
The Intermediate Value Theorem (IVT) states that if the graph of a function
is continuous on an interval , and and differ in sign, then has a zero on . Consequently, the way to answer this question is to determine the signs of on the endpoints of the subintervals - . We can do this by substituting each value for as follows:
assumes positive values for and negative values for . By the IVT, has a zero on .
Example Question #1 : Use The Zeros To Construct A Rough Graph Of A Function
The graph of a function is shown below, with labels on the y-axis hidden.
Determine which of the following functions best fits the graph above.
Use the zeroes of the graph to determine the matching function. Zeroes are values of x where
. In other words, they are points on the graph where the curve touches zero.Visually, you can see that the curve crosses the x-axis when
, , and . Therefore, you need to look for a function that will equal zero at these x values.A function with a factor of
will equal zero when , because the factor of will equal zero. The matching factors for the other two zeroes, and , are and , respectively.The answer choice
has all of these factors, but it is not the answer because it has an additional zero that would be visible on the graph. Notice it has a factor of , which results in a zero at . This additional zero that isn't present in the graph indicates that this cannot be matching function.is the answer because it has all of the required factors and, as a result, the required zeroes, while not having additional zeroes. Notice that the constant coefficient of negative 2 does not affect where the zeroes are.
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.All HiSET: Math Resources
