Chapter 12: Problem 55
In Exercises 55-62, graph the function. Determine the limit (if it exists) by evaluating the corresponding one-sided limits. $$\lim_{x \to 6} \dfrac{|x-6|}{x-6}$$
Short Answer
Expert verified
The limit of the function as \(x\) approaches 6 does not exist.
Step by step solution
01
Identify the Function
The function presented is \(f(x) = \dfrac{|x-6|}{x-6}\). It involves an absolute value and fraction, which will influence its behavior, particularly around \(x = 6\).
02
Understand the Function Behavior
The absolute value, \(|x-6|\), returns the magnitude (or 'positive value') of \(x-6\).\nWhen \(x<6\), \(x-6\) is negative, so \(|x-6|\) would be \(-(x-6)\), making the function \(f(x)= -1\).\nWhen \(x>6\), \(x-6\) is positive, so \(|x-6|\) would be \(x-6\), making the function \(f(x) = 1\).
03
Graph the Function
The function breaking point is at \(x=6\) which is not included in the function domain. When \(x<6\), graph a horizontal line at \(y=-1\), and when \(x>6\), graph a horizontal line at \(y=1\).
04
Determine the one-sided limits
The one-sided limit as \(x\) approaches 6 from the left (\(x<6\)) is \(\lim_{x \to 6^-} f(x) = -1\).\nThe one-sided limit as \(x\) approaches 6 from the right (\(x>6\)) is \(\lim_{x \to 6^+} f(x) = 1\).
05
Determine the limit
Since the one-sided limits are not equal, the limit does not exist. Thus, \(\lim_{x \to 6} \dfrac{|x-6|}{x-6}\) does not exist.
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Absolute Value Function
An absolute value function takes any number and makes it non-negative. It's written \(|x|\), where \(x\) is a number or expression. This function measures the distance from zero on a number line. For example, \(|-3| = 3\) because the distance between -3 and 0 is 3.
With the function \(f(x) = \dfrac{|x-6|}{x-6}\), the absolute value is applied to \(x - 6\). This means that whether \(x - 6\) is positive or negative, \(\left|x - 6\right|\) will be positive.
With the function \(f(x) = \dfrac{|x-6|}{x-6}\), the absolute value is applied to \(x - 6\). This means that whether \(x - 6\) is positive or negative, \(\left|x - 6\right|\) will be positive.
- For \(x < 6\), \(x - 6\) is negative, and \(\left|x - 6\right| = -(x - 6)\).
- For \(x > 6\), \(x - 6\) is positive, so \(\left|x - 6\right| = x - 6\).
One-Sided Limits
One-sided limits involve looking at the behavior of a function as it approaches a point from one side only. These are essential when a function behaves differently on each side of a certain point.
For instance, the one-sided limits of \(\dfrac{|x-6|}{x-6}\) as \(x\) approaches 6 show different behaviors for \(x < 6\) and \(x > 6\):
For instance, the one-sided limits of \(\dfrac{|x-6|}{x-6}\) as \(x\) approaches 6 show different behaviors for \(x < 6\) and \(x > 6\):
- **Left-hand limit:** For \(x < 6\), \(f(x) = -1\), so \(\lim_{x \to 6^-} f(x) = -1\).
- **Right-hand limit:** For \(x > 6\), \(f(x) = 1\), so \(\lim_{x \to 6^+} f(x) = 1\).
Limit Does Not Exist
A limit might not exist when a function does not approach a specific value as \(x\) approaches a point. This commonly occurs when the left-hand limit and right-hand limit at a point are not equal.
Consider the function \(f(x) = \dfrac{|x-6|}{x-6}\):
Consider the function \(f(x) = \dfrac{|x-6|}{x-6}\):
- The left-hand limit at \(x = 6\) is \(-1\).
- The right-hand limit at \(x = 6\) is \(+1\).
Graphing Piecewise Functions
Graphing piecewise functions helps visualize how a function behaves over different intervals. Each piece of the function is graphed separately.
For the function \(f(x) = \dfrac{|x-6|}{x-6}\), the graph has two horizontal lines:
Using different pieces simplifies visualizing complex functions, revealing discontinuities and limits.
For the function \(f(x) = \dfrac{|x-6|}{x-6}\), the graph has two horizontal lines:
- For \(x < 6\), the graph is a line at \(y = -1\).
- For \(x > 6\), the graph is a line at \(y = 1\).
Using different pieces simplifies visualizing complex functions, revealing discontinuities and limits.