Horizontal Compression

Definition

Horizontal compression is a transformation that occurs when the graph of a function is squeezed towards the y-axis, making it narrower. This transformation affects the period of periodic functions, causing them to complete their cycles more quickly. Understanding horizontal compression is essential for analyzing how changes in the input variable impact the overall behavior and appearance of functions.

5 Must Know Facts For Your Next Test

1. Horizontal compression can be mathematically represented by multiplying the input variable by a factor greater than 1 in a function's equation.
2. For a sine or cosine function, if you have a transformation like $$y = A \sin(Bx)$$, then increasing B will compress the graph horizontally.
3. The amount of horizontal compression directly affects the period; specifically, if a function has a period $$T$$, after compression, the new period becomes $$\frac{T}{k}$$ where k is the compression factor.
4. In graphs, horizontal compression can lead to more oscillations within the same interval on the x-axis, making patterns appear closer together.
5. Understanding horizontal compression helps in predicting how quickly a wave-like function oscillates, which is crucial in fields like physics and engineering.

Review Questions

• How does horizontal compression affect the period of a sine function?
  • Horizontal compression impacts the period of a sine function by reducing the time it takes for the function to complete one full cycle. For example, in the function $$y = A \sin(Bx)$$, increasing the value of B leads to a decrease in the period, making the sine wave oscillate more rapidly. This means that with greater horizontal compression, you will see more peaks and troughs over a shorter distance along the x-axis.
• Discuss how you can visually identify horizontal compression in graphs compared to untransformed functions.
  • To visually identify horizontal compression in graphs, you can look for waves or oscillations that appear narrower than their untransformed counterparts. The peaks and troughs will be closer together along the x-axis, indicating that the function completes its cycles more quickly. For example, comparing the graph of $$y = \sin(x)$$ with that of $$y = \sin(2x)$$ shows how doubling the frequency compresses the sine wave horizontally, leading to more cycles being completed within the same interval.
• Evaluate how understanding horizontal compression can influence applications in real-world scenarios such as sound waves or electrical signals.
  • Understanding horizontal compression is crucial when analyzing sound waves or electrical signals because it directly relates to frequency and pitch. In sound waves, for instance, horizontal compression indicates higher frequencies which correspond to higher pitches. Similarly, in electrical signals, adjusting for horizontal compression can optimize signal processing by allowing for quicker data transmission without losing information integrity. This comprehension aids engineers and scientists in designing systems that require precise control over oscillation rates.

Related terms

Amplitude: The amplitude is the maximum distance from the midline to the peak (or trough) of a periodic function, representing its height.

Period: The period is the length of one complete cycle of a periodic function, indicating how long it takes for the function to repeat itself.

Horizontal Stretch: Horizontal stretch is a transformation that makes the graph of a function wider by stretching it away from the y-axis.