Textbook Question
Determine whether each relation defines a function, and give the domain and range. See Examples 1 – 4. x y 0 0 -1 1 -2 2
540
views
0. Review of College Algebra
Functions
3:05 minutesProblem 31
Textbook Question
Determine whether each relation defines y as a function of x. Give the domain and range. See Example 5. y = x²
Verified step by step guidance1
Step 1: Understand the definition of a function. A relation defines y as a function of x if for every x-value there is exactly one corresponding y-value.
Step 2: Analyze the given relation \(y = x^{2}\). For each value of \(x\), calculate \(y\) by squaring \(x\). Since squaring any real number \(x\) gives exactly one value of \(y\), this relation defines \(y\) as a function of \(x\).
Step 3: Determine the domain. The domain is the set of all possible input values \(x\) for which the function is defined. Since \(x\) can be any real number in \(y = x^{2}\), the domain is all real numbers, which can be written as \((-\infty, \infty)\).
Step 4: Determine the range. The range is the set of all possible output values \(y\). Since \(y = x^{2}\) is always greater than or equal to zero (because squaring any real number is non-negative), the range is \([0, \infty)\).
Step 5: Summarize: The relation \(y = x^{2}\) defines \(y\) as a function of \(x\) with domain \((-\infty, \infty)\) and range \([0, \infty)\).
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Video duration:
3mKey Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Definition of a Function
A function is a relation where each input (x-value) corresponds to exactly one output (y-value). To determine if y is a function of x, check that no x-value maps to multiple y-values. For y = x², each x has a unique y, so it defines y as a function of x.
Recommended video:
5:57
Graphs of Common Functions
Domain of a Function
The domain is the set of all possible input values (x-values) for which the function is defined. For y = x², since any real number can be squared, the domain is all real numbers, often written as (-∞, ∞).
Recommended video:
3:43Finding the Domain of an Equation
Range of a Function
The range is the set of all possible output values (y-values) of the function. For y = x², since squaring any real number results in a non-negative value, the range is all real numbers greater than or equal to zero, written as [0, ∞).
Recommended video:
4:22Domain and Range of Function Transformations
Related Videos
Related Practice