Chapter 1: Problem 40
\(33-44\) Find the domain and sketch the graph of the function. $$g(x)=\frac{|x|}{x^{2}}$$
Short Answer
Expert verified
The domain is all real numbers except 0. Graph has asymptotes at \(x = 0\).
Step by step solution
01
- Understand the function
We start by analyzing the given function \(g(x) = \frac{|x|}{x^{2}}\). This function consists of an absolute value section \(|x|\) in the numerator and a quadratic \(x^2\) in the denominator.
02
- Identify restrictions for the domain
The domain of a function is determined by the values of \(x\) that make the function undefined. \(g(x)\) is undefined where the denominator is zero. Therefore, \(x^2 = 0\) tells us \(x = 0\). Thus, \(x = 0\) must be excluded from the domain.
03
- State the domain
Considering the restriction found in the previous step, the function is defined for all real numbers except \(x = 0\). Thus, the domain of \(g(x)\) is all real numbers except 0, expressed as \(x \in \mathbb{R} \setminus \{0\}\).
04
- Understand the behavior of the function
Next, we analyze how the function acts over different intervals. For \(x > 0\), the function simplifies to \(g(x) = \frac{x}{x^2} = \frac{1}{x}\). For \(x < 0\), the function simplifies to \(g(x) = \frac{-x}{x^2} = -\frac{1}{x}\).
05
- Graph the function
The function can be graphed using its different forms on either side of zero. For \(x > 0\), the graph is that of \(y = \frac{1}{x}\), and for \(x < 0\), the graph is \(y = -\frac{1}{x}\). The vertical asymptote at \(x = 0\) indicates the function is undefined there and the graph has a discontinuity.
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Graphing Functions
To understand a function fully, creating its graph can be incredibly helpful. A graph visually represents the behavior of a function over a range of values.
In the case of the function \(g(x) = \frac{|x|}{x^{2}}\), the graph consists of two separate parts due to the absolute value and the quadratic components. There is a critical point at \(x = 0\) where the function is undefined. This leads to a vertical asymptote, which the graph approaches but never touches or crosses.
In the case of the function \(g(x) = \frac{|x|}{x^{2}}\), the graph consists of two separate parts due to the absolute value and the quadratic components. There is a critical point at \(x = 0\) where the function is undefined. This leads to a vertical asymptote, which the graph approaches but never touches or crosses.
- For \(x > 0\), the graph depicts the function \(y = \frac{1}{x}\), which is a hyperbola situated in the first quadrant.
- For \(x < 0\), the graph changes to \(y = -\frac{1}{x}\), creating another hyperbolic shape in the third quadrant.
Absolute Value Functions
Absolute value functions introduce unique attributes to functions due to their nature of always being non-negative. The absolute value of \(x\), written as \(|x|\), equals \(x\) if \(x\) is positive or zero, and \(-x\) if \(x\) is negative.
In the expression \(g(x) = \frac{|x|}{x^{2}}\), the absolute value affects the behavior depending on whether \(x\) is positive or negative, ensuring that the numerator is always positive for positive \(x\) or negative \(x\).
This results in:
In the expression \(g(x) = \frac{|x|}{x^{2}}\), the absolute value affects the behavior depending on whether \(x\) is positive or negative, ensuring that the numerator is always positive for positive \(x\) or negative \(x\).
This results in:
- \(g(x) = \frac{1}{x}\) when \(x > 0\).
- \(g(x) = -\frac{1}{x}\) when \(x < 0\).
Behavior of Functions
Understanding the behavior of a function involves exploring how it behaves over its domain. For \(g(x) = \frac{|x|}{x^{2}}\), the behavior changes depending on whether \(x\) is positive or negative.
Key observations help depict its behavior efficiently:
Key observations help depict its behavior efficiently:
- For \(x > 0\), \(g(x)\) simplifies to \(\frac{1}{x}\), showing a decreasing curve from the positive y-axis towards zero but never reaching it, representing an asymptotic behavior.
- For \(x < 0\), \(g(x)\) becomes \(-\frac{1}{x}\), indicating an increase towards zero from negative y-values, but similarly never reaching zero.
- There's an important exclusion at \(x = 0\), since the function is undefined due to division by zero. This point forms a significant break, called a discontinuity. As \(x\) approaches zero from either direction, the values of \(g(x)\) become exceedingly large in magnitude, indicating the presence of a vertical asymptote.