Vertical Stretch

Definition

Vertical stretch is a transformation that changes the scale of a function along the y-axis, effectively stretching or compressing the function's graph in the vertical direction. This concept is particularly relevant in the context of evaluating and graphing logarithmic functions.

5 Must Know Facts For Your Next Test

1. The vertical stretch of a logarithmic function $f(x) = ext{log}_b(x)$ is controlled by the base $b$. As the base $b$ increases, the function becomes more vertically stretched.
2. Increasing the base $b$ of a logarithmic function results in a flatter, more horizontally oriented graph, while decreasing the base $b$ leads to a steeper, more vertically oriented graph.
3. The vertical stretch factor of a logarithmic function $f(x) = ext{log}_b(x)$ is given by $rac{1}{ ext{ln}(b)}$, where $ ext{ln}(b)$ represents the natural logarithm of the base $b$.
4. Vertical stretches of logarithmic functions can be combined with other transformations, such as translations, to create more complex graphs.
5. Understanding the effects of vertical stretch on logarithmic functions is crucial for accurately evaluating and graphing these functions, which are widely used in various applications, including finance, science, and engineering.

Review Questions

• Explain how the base $b$ of a logarithmic function $f(x) = ext{log}_b(x)$ affects the vertical stretch of the graph.
  • The base $b$ of a logarithmic function $f(x) = ext{log}_b(x)$ directly influences the vertical stretch of the graph. As the base $b$ increases, the function becomes more vertically stretched, resulting in a flatter, more horizontally oriented graph. Conversely, decreasing the base $b$ leads to a steeper, more vertically oriented graph. The vertical stretch factor is given by $rac{1}{ ext{ln}(b)}$, where $ ext{ln}(b)$ represents the natural logarithm of the base $b$. Understanding this relationship between the base and the vertical stretch is crucial for accurately evaluating and graphing logarithmic functions.
• Describe how the vertical stretch of a logarithmic function can be combined with other transformations to create more complex graphs.
  • The vertical stretch of a logarithmic function can be combined with other transformations, such as translations, to create more complex graphs. For example, the function $f(x) = a ext{log}_b(x) + c$, where $a$ represents the vertical stretch factor and $c$ represents a vertical translation, allows for the creation of a wide range of logarithmic graphs. By adjusting the values of $a$ and $c$, the graph can be vertically stretched or compressed, and shifted up or down, respectively. These combined transformations enable the graphing of more intricate logarithmic functions, which are essential in various applications.
• Analyze the importance of understanding vertical stretch in the context of evaluating and graphing logarithmic functions.
  • Understanding the concept of vertical stretch is crucial when evaluating and graphing logarithmic functions. The vertical stretch of a logarithmic function $f(x) = ext{log}_b(x)$ is directly determined by the base $b$, with a higher base leading to a more vertically stretched graph and a lower base resulting in a steeper, more vertically oriented graph. This knowledge allows for the accurate interpretation and representation of logarithmic functions, which are widely used in fields such as finance, science, and engineering. Mastering the relationship between the base and the vertical stretch enables students to effectively evaluate, graph, and apply logarithmic functions in a variety of real-world scenarios.

Related terms

Logarithmic Function: A logarithmic function is a function of the form $f(x) = ext{log}_b(x)$, where $b$ is the base of the logarithm. Logarithmic functions exhibit a characteristic curved shape.

Transformation: A transformation is a change applied to a function that alters its graph, such as translation, reflection, dilation, or stretch.

Dilation: Dilation is a transformation that changes the scale of a function, either expanding or contracting the graph along one or both axes.