Skip to main content
Ch. R - Algebra Review
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161Not the one you use?Change textbook
Chapter 1, Problem 5

Fill in the blank(s) to correctly complete each sentence.
The graph of ƒ(x) = -√x is a reflection of the graph of y = √x across the ___-axis.

Verified step by step guidance
1
Identify the original function and the transformed function. The original function is \(y = \sqrt{x}\), and the transformed function is \(f(x) = -\sqrt{x}\).
Recognize that the negative sign in front of the square root affects the output values (the \(y\)-values) of the function, changing their sign.
Understand that changing the sign of the \(y\)-values corresponds to reflecting the graph across the \(x\)-axis.
Therefore, the graph of \(f(x) = -\sqrt{x}\) is a reflection of the graph of \(y = \sqrt{x}\) across the \(x\)-axis.
Fill in the blank with '\(x\)' to complete the sentence: 'The graph of \(f(x) = -\sqrt{x}\) is a reflection of the graph of \(y = \sqrt{x}\) across the \(x\)-axis.'

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
2m
Was this helpful?

Key Concepts

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

Square Root Function

The square root function, y = √x, produces the principal (non-negative) root of x and is defined for x ≥ 0. Its graph starts at the origin and increases slowly, forming a curve in the first quadrant. Understanding this base function is essential before analyzing transformations.
Recommended video:
2:20
Imaginary Roots with the Square Root Property

Reflection Across an Axis

Reflection across an axis means flipping a graph over that axis, creating a mirror image. Reflecting a function y = f(x) across the x-axis changes it to y = -f(x), inverting all y-values. This concept helps identify how the graph of y = -√x relates to y = √x.
Recommended video:
5:00
Reflections of Functions

Function Transformations

Function transformations include shifts, stretches, compressions, and reflections that alter a graph's position or shape. Recognizing how multiplying a function by -1 reflects it across the x-axis is key to completing the sentence about the graph of ƒ(x) = -√x.
Recommended video:
4:22
Domain and Range of Function Transformations