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Ch. 2 - Graphs and Functions
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063Not the one you use?Change textbook
Chapter 3, Problem 8

To answer each question, refer to the following basic graphs. Which one is the graph of ƒ(x)=√x? What is its domain?

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1
Recall the definition of the function ƒ(x) = \(\sqrt{x}\), which represents the principal (non-negative) square root of x.
Understand that the graph of ƒ(x) = \(\sqrt{x}\) starts at the point (0,0) because \(\sqrt{0}\) = 0, and it only includes values where x is greater than or equal to zero, since the square root of a negative number is not a real number.
Identify the graph that begins at the origin (0,0) and increases gradually to the right, forming a curve that rises slowly as x increases; this is the characteristic shape of the square root function.
Determine the domain of ƒ(x) = \(\sqrt{x}\) by considering all x-values for which the function is defined. Since the square root requires non-negative inputs, the domain is all real numbers x such that x \(\geq\) 0.
Express the domain in interval notation as [0, \(\infty\)), indicating that the function includes zero and all positive real numbers.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Square Root Function

The square root function, denoted as ƒ(x) = √x, outputs the non-negative value whose square is x. It is defined only for x ≥ 0 because the square root of a negative number is not a real number. Understanding this function's shape helps in identifying its graph.
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Domain of a Function

The domain of a function is the set of all input values (x-values) for which the function is defined. For ƒ(x) = √x, the domain includes all real numbers x ≥ 0, since the square root of negative numbers is not real. Recognizing the domain is essential for graph interpretation.
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Graphing Basic Functions

Graphing basic functions involves plotting points that satisfy the function's equation and understanding their general shape. The graph of ƒ(x) = √x starts at the origin (0,0) and increases slowly to the right, forming a curve in the first quadrant. Familiarity with these shapes aids in matching functions to their graphs.
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