Chapter 13: Problem 35
Use a calculator to graph the function \(y=2^{|x|}\).
Short Answer
Expert verified
The graph of \(y = 2^{|x|}\) is a V-shaped curve, symmetric around the y-axis, with exponential arms extending away from it.
Step by step solution
01
Understand the Function
The given function is \(y = 2^{|x|}\). This is an exponential function where the base is 2, and the exponent is the absolute value of \(x\). Since the exponent is always non-negative due to the absolute value, the function will always produce positive y-values.
02
Determine Key Points
Calculate some key points to understand the behavior of the graph. Evaluate the function at \(-2, -1, 0, 1,\) and \(2\):1. \(x = -2\), \(y = 2^{|-2|} = 2^2 = 4\)2. \(x = -1\), \(y = 2^{|-1|} = 2^1 = 2\)3. \(x = 0\), \(y = 2^{|0|} = 2^0 = 1\)4. \(x = 1\), \(y = 2^{|1|} = 2^1 = 2\)5. \(x = 2\), \(y = 2^{|2|} = 2^2 = 4\)
03
Analyze Symmetry
The function \(y = 2^{|x|}\) is symmetric with respect to the y-axis. This is because \(|x| = |-x|\), which results in the same y-value for \(x\) and \(-x\).
04
Graph the Function
Using a graphing calculator, plot the points \((-2, 4)\), \((-1, 2)\), \((0, 1)\), \((1, 2)\), and \((2, 4)\). Connect these points with a smooth curve to form a V-shaped graph that increases exponentially away from the y-axis. The left side of the graph mirrors the right due to symmetry.
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Exponential Functions
Exponential functions are mathematical expressions where a constant base is raised to a variable exponent. In the context of the function \(y = 2^{|x|}\), the base is 2. Exponential growth occurs as the absolute value of \(x\) increases, leading to larger results for \(y\).
Here, the exponent is \(|x|\), making it particularly interesting since absolute values always yield non-negative numbers. This ensures \(y\) is always positive. Such a function grows rapidly as \(|x|\) increases, demonstrating exponential growth in both positive and negative directions of \(x\).
To put it simply:
Here, the exponent is \(|x|\), making it particularly interesting since absolute values always yield non-negative numbers. This ensures \(y\) is always positive. Such a function grows rapidly as \(|x|\) increases, demonstrating exponential growth in both positive and negative directions of \(x\).
To put it simply:
- Base: Constant (2 in this case)
- Exponent: Variable (here, the absolute value of \(x\))
- Output: Always positive, increases exponentially
Absolute Value
The absolute value function, denoted as \(|x|\), always returns the non-negative version of \(x\). This means whether \(x\) is positive or negative, \(|x|\) is the non-negative counterpart. In our function \(y = 2^{|x|}\), the absolute value significantly influences the outcome of the function.
For instance, \(2^{|x|}\) means whether \(x\) is 2 or -2, \(|x| = 2\). This feature simplifies understanding; you don't need separate calculations for negative and positive values of \(x\).
Remember:
For instance, \(2^{|x|}\) means whether \(x\) is 2 or -2, \(|x| = 2\). This feature simplifies understanding; you don't need separate calculations for negative and positive values of \(x\).
Remember:
- \(|x| = x\) if \(x \geq 0\)
- \(|x| = -x\) if \(x < 0\)
- This ensures the output of \(y = 2^{|x|}\) remains consistent in all cases.
Symmetry in Graphs
Symmetry in graphs often simplifies understanding and plotting. For the function \(y = 2^{|x|}\), there is symmetry about the y-axis. This is because \(|x|\) produces identical results for both positive \(x\) and negative \(x\).
This particular symmetry tells us:
This particular symmetry tells us:
- The right side of the graph mirrors the left side.
- You only need to evaluate the function in one half of the plane to understand its full behavior.
- This V-shape resulting from the symmetry is a hallmark of functions involving absolute values.
Graphing Calculator Usage
Using a graphing calculator can significantly aid in visualizing functions, especially ones as dynamic as exponential functions. Graphing \(y = 2^{|x|}\) can initially seem tricky due to the absolute values and exponential growth, but a calculator streamlines understanding.
Here's a simple process:
Here's a simple process:
- Enter the function into the graphing calculator: Most calculators have a function mode where you can input \(y = 2^{|x|}\).
- Set a suitable range: Start with a small window for \(x\) and \(y\) to see the central part of the graph before expanding it.
- Analyze symmetry: Notice how both halves of the graph mirror across the y-axis, reflecting the principles of symmetry.
- Use trace features: Many calculators allow you to trace the graph to find exact points easily, reinforcing the plotted values.