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Example Questions
Example Question #5 : How To Find The Domain Of A Function
What is the domain of the function?
All real numbers
All positive integers
All real numbers
The domain of f(x) is all the values of x for which f(x) is defined.
f(x) has no square roots or denominators, so it will always be defined; there are no restrictions on x because any and all values will lead to a real result.
Therefore, the domain is the set of all real numbers.
Example Question #7 : How To Find The Domain Of A Function
Which of the following represents the domain of where:
is all real numbers
is all real numbers
Using our properties of exponents, we could rewrite as
This means that when we input , we first subtract 2, then take this to the fourth power, then take the fifth root, and then add three. We want to look at these steps individually and see whether there are any values that wouldn’t work at each step. In other words, we want to know which
values we can put into our function at each step without encountering any problems.
The first step is to subtract 2 from . The second step is to take that result and raise it to the fourth power. We can subtract two from any number, and we can take any number to the fourth power, which means that these steps don't put any restrictions on
.
Then we must take the fifth root of a value. The trick to this problem is recognizing that we can take the fifth root of any number, positive or negative, because the function is defined for any value of
; thus the fact that
has a fifth root in it doesn't put any restrictions on
, because we can add three to any number; therefore, the domain for
is all real values of
.
Example Question #8 : How To Find The Domain Of A Function
What is the domain of the given function?
x ≠ –3
All real numbers
x ≠ 0
x ≠ 3
x ≠ 3, –3
x ≠ –3
The domain of the function is all real numbers except x = –3. When x = –3, f(–3) is undefined.
Example Question #1 : How To Find The Domain Of A Function
Find the domain of the given function:
All real numbers x such that x ≠ 3, 0
All real numbers x such that x ≠ 1, 0
All real numbers x such that x ≠ 0
All real numbers
All real numbers x such that x ≠ 3
All real numbers x such that x ≠ 3, 0
When x = 0 or x = 3, the function is undefined due to its denominator.
Thus the domain is all real numbers x, such that x is not equal to 0 or 3.
Example Question #1 : Algebraic Functions
Find the domain of the function:
All real numbers except for –2
All real numbers except for 1
All real numbers
0
All real numbers except for 1
If a value of x makes the denominator of a equation zero, that value is not part of the domain. This is true, even here where the denominator can be "cancelled" by factoring the numerator into
and then cancelling the from the numerator and the denominator.
This new expression, is the equation of the function, but it will have a hole at the point where the denominator originally would have been zero. Thus, this graph will look like the line
with a hole where
, which is
.
Thus the domain of the function is all values such that
Example Question #1 : How To Use The Quadratic Function
If x2 + 2x - 1 = 7, which answers for x are correct?
x = -3, x = 4
x = -5, x = 1
x = -4, x = 2
x = 8, x = 0
x = -4, x = -2
x = -4, x = 2
x2 + 2x - 1 = 7
x2 + 2x - 8 = 0
(x + 4) (x - 2) = 0
x = -4, x = 2
Example Question #2 : How To Use The Quadratic Function
Which of the following quadratic equations has a vertex located at ?
The vertex form of a parabola is given by the equation:
, where the point
is the vertex, and
is a constant.
We are told that the vertex must occur at , so let's plug this information into the vertex form of the equation.
will be 3, and
will be 4.
Let's now expand by using the FOIL method, which requires us to multiply the first, inner, outer, and last terms together before adding them all together.
We can replace with
.
Next, distribute the .
Notice that in all of our answer choices, the first term is . If we let
, then we would have
in our equation. Let's see what happens when we substitute
for
.
Example Question #2 : How To Use The Quadratic Function
Use the quadratic equation to solve for .
None of the other answers
We take a polynomial in the form
and enter the corresponding coefficients into the quadratic equation.
. We normally expect to have two answers given by the sign
.
So,
Example Question #3 : How To Use The Quadratic Function
Define function as follows:
Given that and
, evaluate
.
No such value exists.
No such value exists.
We solve for in the equation
This is the only solution. Since it is established that is not equal to 5, the correct response is that no such value exists.
Example Question #4 : How To Use The Quadratic Function
Define function as follows:
Given that and
, evaluate
.
No such value exists.
Solve for in the equation
Either , in which case
, which is already established to be untrue, or
, in which case
. This is the correct response.
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