Skip to main content
Ch. R - Algebra Review
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161Not the one you use?Change textbook
Chapter 1, Problem 53

Evaluate each expression. See Example 5. |-8|

Verified step by step guidance
1
Recognize that the expression involves the absolute value function, denoted by vertical bars \(|\cdot|\), which gives the non-negative value of the number inside it.
Recall the definition of absolute value: for any real number \(x\), \(|x| = x\) if \(x \geq 0\), and \(|x| = -x\) if \(x < 0\).
Identify the number inside the absolute value: here it is \(-8\), which is less than zero.
Apply the absolute value definition for negative numbers: \(|-8| = -(-8)\).
Simplify the expression by removing the double negative to find the absolute value.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1m
Was this helpful?

Key Concepts

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

Absolute Value

The absolute value of a number is its distance from zero on the number line, regardless of direction. It is always non-negative, so |-8| equals 8. This concept helps in understanding magnitude without considering sign.
Recommended video:
7:28
Evaluate Composite Functions - Values Not on Unit Circle

Number Line Representation

Visualizing numbers on a number line aids in grasping absolute value. Negative numbers lie to the left of zero, and their absolute value corresponds to the positive distance from zero, reinforcing the idea that absolute value measures magnitude only.
Recommended video:
3:31
Introduction to Complex Numbers

Basic Arithmetic Operations

Understanding how to evaluate expressions involves applying arithmetic rules correctly. For absolute value, this means recognizing that the operation transforms negative inputs into positive outputs, which is essential for simplifying and solving expressions.
Recommended video:
04:12
Algebraic Operations on Vectors