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Example Questions
Example Question #2661 : Act Math
Define function as follows:
On which of the following restrictions of the domain of would
not exist?
None of the other responses gives a correct answer.
has an inverse on a given domain if and only if there are no two distinct values on the domain
such that
.
is a quadratic function, so its graph is a parabola. The key is to find the
-intercept of the vertex of the parabola, which can be found by completing the square:
The vertex happens at , so the interval which contains this value will have at least one pair
such that
. The correct choice is
.
Example Question #13 : Algebraic Functions
Define function as follows:
On which of the following restrictions of the domain of would
not exist?
has an inverse on a given domain if and only if there are no two distinct values on the domain
such that
.
has a sinusoidal wave as its graph, with period
; it begins at a relative maximum of
and has a relative maximum or minimum every
units. Therefore, any interval containing an integer multiple of
will have at least two distinct values
such that
.
The only interval among the choices that includes a multiple of is
:
.
This is the correct choice.
Example Question #13 : Algebraic Functions
Define function as follows:
In which of the following ways could the domain of be restricted so that
does not have an inverse?
None of the other responses give a correct answer.
None of the other responses give a correct answer.
If , then
. By the addition property of inequality, if
, then
. Therefore, if
,
.
Consequently, there can be no such that
, regardless of how the domain is restricted.
will have an inverse regardless of any domain restriction.
Example Question #13 : Algebraic Functions
Consider the following statement to be true:
If a fish is a carnivore, then it is a shark.
Which of the following statements must also be true?
If a fish is not a carnivore, then it is not a shark.
If a fish is not a shark, then it is not a carnivore.
All fish are sharks.
If a fish is a shark, then it is a carnivore.
If a fish is not a shark, then it is a carnivore.
If a fish is not a shark, then it is not a carnivore.
The statement "If a fish is a carnivore, then it is a shark", can be simplified to "If X, then Y", where X represents the hypothesis (i.e. "If a fish is a carnivore...") and Y represents the conclusion (i.e. "...then it is a shark").
Answer choice A is a converse statement, and not necessarily true: ("If Y, then X").
Answer choice C is an inverse statement, and not necessarily true: ("If not X, then not Y").
Answer choice D states "If not Y, then X", which is false.
Answer choice E "All fish are sharks" is also false, and cannot be deduced from the given information.
Answer choice B is a contrapositive, and is the only statement that must be true. "If not Y, then not X."
The statement given in the question suggests that all carnivorous fish are sharks. So if a fish is not a shark then it cannot be carnivorous.
Example Question #2662 : Act Math
If f(x)=3x and g(x)=2x+2, what is the value of f(g(x)) when x=3?
22
24
18
20
24
With composition of functions (as with the order of operations) we perform what is inside of the parentheses first. So, g(3)=2(3)+2=8 and then f(8)=24.
Example Question #1 : Algebraic Functions
g(x) = 4x – 3
h(x) = .25πx + 5
If f(x)=g(h(x)). What is f(1)?
42
13π + 3
π + 17
19π – 3
4
π + 17
First, input the function of h into g. So f(x) = 4(.25πx + 5) – 3, then simplify this expression f(x) = πx + 20 – 3 (leave in terms of π since our answers are in terms of π). Then plug in 1 for x to get π + 17.
Example Question #2791 : Sat Mathematics
If 7y = 4x - 12, then x =
Adding 12 to both sides and dividing by 4 yields (7y+12)/4.
Example Question #2663 : Act Math
What is ?
Example Question #4 : Algebraic Functions
If F(x) = 2x2 + 3 and G(x) = x – 3, what is F(G(x))?
2x2 – 12x +21
6x2 – 12x
2x2 + 12x +18
2x2
6x2 + 5x
2x2 – 12x +21
A composite function substitutes one function into another function and then simplifies the resulting expression. F(G(x)) means the G(x) gets put into F(x).
F(G(x)) = 2(x – 3)2 + 3 = 2(x2 – 6x +9) + 3 = 2x2 – 12x + 18 + 3 = 2x2 – 12x + 21
G(F(x)) = (2x2 +3) – 3 = 2x2
Example Question #2791 : Sat Mathematics
If a(x) = 2x3 + x, and b(x) = –2x, what is a(b(2))?
503
–503
132
–132
128
–132
When functions are set up within other functions like in this problem, the function closest to the given variable is performed first. The value obtained from this function is then plugged in as the variable in the outside function. Since b(x) = –2x, and x = 2, the value we obtain from b(x) is –4. We then plug this value in for x in the a(x) function. So a(x) then becomes 2(–43) + (–4), which equals –132.
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