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Example Questions
Example Question #1 : How To Find Domain And Range Of The Inverse Of A Relation
What is the range of the function y = x2 + 2?
undefined
y ≥ 2
{2}
{–2, 2}
all real numbers
y ≥ 2
The range of a function is the set of y-values that a function can take. First let's find the domain. The domain is the set of x-values that the function can take. Here the domain is all real numbers because no x-value will make this function undefined. (Dividing by 0 is an example of an operation that would make the function undefined.)
So if any value of x can be plugged into y = x2 + 2, can y take any value also? Not quite! The smallest value that y can ever be is 2. No matter what value of x is plugged in, y = x2 + 2 will never produce a number less than 2. Therefore the range is y ≥ 2.
Example Question #2 : How To Find Domain And Range Of The Inverse Of A Relation
Which of the following values of x is not in the domain of the function y = (2x – 1) / (x2 – 6x + 9) ?
1/2
3
2
0
–1/2
3
Values of x that make the denominator equal zero are not included in the domain. The denominator can be simplified to (x – 3)2, so the value that makes it zero is 3.
Example Question #32 : Algebraic Functions
Given the relation below:
{(1, 2), (3, 4), (5, 6), (7, 8)}
Find the range of the inverse of the relation.
The domain of a relation is the same as the range of the inverse of the relation. In other words, the x-values of the relation are the y-values of the inverse.
Example Question #33 : Algebraic Functions
What is the range of the function y = x2 + 2?
{2}
{–2, 2}
undefined
y ≥ 2
all real numbers
y ≥ 2
The range of a function is the set of y-values that a function can take. First let's find the domain. The domain is the set of x-values that the function can take. Here the domain is all real numbers because no x-value will make this function undefined. (Dividing by 0 is an example of an operation that would make the function undefined.)
So if any value of x can be plugged into y = x2 + 2, can y take any value also? Not quite! The smallest value that y can ever be is 2. No matter what value of x is plugged in, y = x2 + 2 will never produce a number less than 2. Therefore the range is y ≥ 2.
Example Question #34 : Algebraic Functions
What is the smallest value that belongs to the range of the function ?
We need to be careful here not to confuse the domain and range of a function. The problem specifically concerns the range of the function, which is the set of possible numbers of . It can be helpful to think of the range as all the possible y-values we could have on the points on the graph of .
Notice that has in its equation. Whenever we have an absolute value of some quantity, the result will always be equal to or greater than zero. In other words, |4-x| 0. We are asked to find the smallest value in the range of , so let's consider the smallest value of , which would have to be zero. Let's see what would happen to if .
This means that when , . Let's see what happens when gets larger. For example, let's let .
As we can see, as gets larger, so does . We want to be as small as possible, so we are going to want to be equal to zero. And, as we already determiend, equals when .
The answer is .
Example Question #2 : How To Find Domain And Range Of The Inverse Of A Relation
If , then find
is the same as .
To find the inverse simply exchange and and solve for .
So we get which leads to .
Example Question #3 : How To Find Domain And Range Of The Inverse Of A Relation
If , then which of the following is equal to ?
Example Question #3 : How To Find Domain And Range Of The Inverse Of A Relation
Given the relation below, identify the domain of the inverse of the relation.
The inverse of the relation does not exist.
The domain of the inverse of a relation is the same as the range of the original relation. In other words, the y-values of the relation are the x-values of the inverse.
For the original relation, the range is: .
Thus, the domain for the inverse relation will also be .
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