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Example Questions
Example Question #1662 : High School Math

If the function is depicted here, which answer choice graphs
?
Example Question #291 : Equations / Inequalities
Which of the following graphs correctly represents the quadratic inequality below (solutions to the inequalities are shaded in blue)?
To begin, we analyze the equation given: the base equation,  is shifted left one unit and vertically stretched by a factor of 2. The graph of the equationÂ
 is:
To solve the inequality, we need to take a test point and plug it in to see if it matches the inequality. The only points that cannot be used are those directly on our parabola, so let's use the origin . If plugging this point in makes the inequality true, then we shade the area containing that point (in this case, outside the parabola); if it makes the inequality untrue, then the opposite side is shaded (in this case, the inside of the parabola). Plugging the numbers in shows:
Simplified as:
Which is not true, so the area inside of the parabola should be shaded, resulting in the following graph:
Example Question #63 : Polynomial Functions
How many zeroes does the following polynomial have?
 is a degree 3 polynomial, so we don't have any easy formulas for calculating possible roots--we just have to check individual values to see if they work. We can use the rational root test to narrow the options down. Remember, if we have a polynomial of the formÂ
 then any rational root will be of the form p/q where p is a factor ofÂ
 and q is a factor ofÂ
. Fortunately in this case,Â
 so we only need to check the factors ofÂ
, which is -15. Let's start with the easiest one: 1.
 It doesn't work.
If we try the next number up, 3, we get this:
 It worked! So we know that a factor of our polynomial isÂ
. We can divide this factor out:
Â
Â
and now we need to see if  has any roots. We can actually solve quadratics so this is easier.
There aren't any real numbers that square to get -5 so this has no roots. Thus, Â only has one root.
Example Question #64 : Polynomial Functions
 is a polynomial function.Â
,Â
.
True or false: By the Intermediate Value Theorem,  cannot have a zero on the intervalÂ
.
False
True
False
As a polynomial function, the graph of  is continuous. By the Intermediate Value Theorem, ifÂ
 orÂ
, then there must exist a valueÂ
 such thatÂ
.Â
Set  andÂ
. It is not true thatÂ
, so the Intermediate Value Theorem does not prove that there existsÂ
 such thatÂ
. However, it does not disprove that such a value exists either. For example, observe the graphs below:
Both are polynomial graphs fitting the given conditions, but the only the equation graphed at right has a zero on .
Example Question #65 : Polynomial Functions
True or false:
The polynomial  hasÂ
 as a factor.
False
True
True
One way to answer this question is as follows:
Let . By a corollary of the Factor Theorem,Â
 is divisible byÂ
 if and only if the sum of its coefficients (accounting for minus symbols) is 0.Â
 hasÂ
as its coefficient sum, so  is indeed divisible byÂ
.
Example Question #5 : Graphing Polynomials
True or false:
The polynomial  hasÂ
 as a factor.
False
True
False
Let . By a corollary of the Factor Theorem,Â
 is divisible byÂ
 if and only if the alternating sum of its coefficients (accounting for minus symbols) is 0.
To find this alternating sum, it is necessary to reverse the symbol before all terms of odd degree. In , there is one such terms, the
 term, so the alternating coefficient sum is Â
,
so  is not divisible byÂ
.
Example Question #66 : Polynomial Functions
 is a polynomial function.Â
 andÂ
.
True or false: By the Intermediate Value Theorem,  must have a zero on the intervalÂ
.
True
False
True
As a polynomial function, the graph of  is continuous. By the Intermediate Value Theorem, ifÂ
 orÂ
, then there must exist a valueÂ
 such thatÂ
.Â
Setting , and looking at the second condition alone, this becomes: IfÂ
, then there must exist a valueÂ
 such thatÂ
 - that is,Â
 must have a zero onÂ
. The conditions of this statement are met , since Â
 - andÂ
 - soÂ
 does have a zero on this interval.
Example Question #7 : Graphing Polynomials
Let  be an even polynomial function withÂ
 as a factor.Â
True or false: It follows that  is also a factor ofÂ
.
True
False
True
By the Factor Theorem,  is a factor of a polynomialÂ
 if and only ifÂ
. It is given thatÂ
 is a factor ofÂ
, so it follows thatÂ
.
 is an even function, so, by definition, for allÂ
 in its domain,Â
. SettingÂ
,Â
; by substitution,Â
. It follows thatÂ
 is also a factor ofÂ
, making the statement true.Â
Example Question #132 : Functions And Graphs
Which of the following graphs matches the function ?
Start by visualizing the graph associated with the function :
Terms within the parentheses associated with the squared x-variable will shift the parabola horizontally, while terms outside of the parentheses will shift the parabola vertically. In the provided equation, 2 is located outside of the parentheses and is subtracted from the terms located within the parentheses; therefore, the parabola in the graph will shift down by 2 units. A simplified graph of  looks like this:
Remember that there is also a term within the parentheses. Within the parentheses, 1 is subtracted from the x-variable; thus, the parabola in the graph will shift to the right by 1 unit. As a result, the following graph matches the given function  :
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