Discover a wealth of knowledge at Westonci.ca, where experts provide answers to your most pressing questions. Get the answers you need quickly and accurately from a dedicated community of experts on our Q&A platform. Discover detailed answers to your questions from a wide network of experts on our comprehensive Q&A platform.

Select the correct statements in the passage.

Hillary's teacher asked her to write a description of the transformations to the parent cosine function that would result in this function.

[tex]\[ h(x) = -3 \cos (2x - \pi) + 4 \][/tex]

Which statements in her description are true about function [tex]\( h \)[/tex]?

A. To create the graph of function [tex]\( h \)[/tex], the graph of the parent function is horizontally compressed by a factor of [tex]\(\frac{1}{2}\)[/tex]. Then it undergoes a phase shift left [tex]\(\frac{\pi}{2}\)[/tex] units. Next, it is vertically stretched by a factor of -3 and vertically shifted up 4 units.

B. The period of function [tex]\( h \)[/tex] is half the period of the parent function, and it has an amplitude 3 units greater than that of the parent function.

Sagot :

Let's break down the transformations step by step based on the function [tex]\( h(x) = -3 \cos (2x - \pi) + 4 \)[/tex]:

### Step 1: Horizontal Compression
The term [tex]\(2x\)[/tex] inside the cosine function indicates a horizontal compression by a factor of [tex]\( \frac{1}{2} \)[/tex].

### Step 2: Phase Shift
The term [tex]\( -\pi \)[/tex] inside the cosine function indicates a phase shift. We solve for the shift by setting the inside equal to 0:
[tex]\[ 2x - \pi = 0 \implies x = \frac{\pi}{2} \][/tex]
This means the graph is shifted to the right by [tex]\( \frac{\pi}{2} \)[/tex] units.

### Step 3: Vertical Compression and Shift
\- The leading coefficient [tex]\( -3 \)[/tex] represents a vertical stretch by a factor of 3 and a reflection across the x-axis.
\- The constant term [tex]\( +4 \)[/tex] represents a vertical shift upward by 4 units.

### Step 4: Period
The period of the parent cosine function is [tex]\( 2\pi \)[/tex]. Given the horizontal compression,
[tex]\[ \text{New Period} = \frac{2\pi}{2} = \pi \][/tex]

### Step 5: Amplitude
The amplitude of the parent cosine function is 1. Given the vertical stretch,
[tex]\[ \text{New Amplitude} = | -3 | = 3 \][/tex]

### Analysis of Statements
Let's analyze the statements provided in Hillary's description:

1. "The graph of the parent function is horizontally compressed by a factor of [tex]\( \frac{1}{\frac{1}{3}} \)[/tex]."
- This statement is incorrect. The horizontal compression factor is actually [tex]\( \frac{1}{2} \)[/tex].

2. "Phase shift left [tex]\( \frac{7}{2} \)[/tex] units."
- This statement is incorrect. The phase shift is to the right by [tex]\( \frac{\pi}{2} \)[/tex] units.

3. "Vertically compressed by a factor of -3 and vertically shifted up 4 units."
- This statement is partially correct regarding the vertical compression (it involves a reflection and stretch by 3). The shift up 4 units part is correct.

4. "The period of function [tex]\( h \)[/tex] is half the period of the parent function."
- This statement is correct. The new period is [tex]\( \pi \)[/tex], which is half of [tex]\( 2\pi \)[/tex].

5. "It has an amplitude 3 units greater than that of the parent function."
- This statement is incorrect. The amplitude is 3, which is not 3 units greater but rather the absolute coefficient of the cosine.

### Correct Statements
The correct and true statements about function [tex]\( h(x) \)[/tex] from Hillary's description would therefore be:

1. It undergoes a horizontal compression by a factor of [tex]\( \frac{1}{2} \)[/tex].
2. It undergoes a phase shift to the right by [tex]\( \frac{\pi}{2} \)[/tex] units.
3. It is vertically stretched by a factor of 3, reflected across the x-axis, and shifted upward by 4 units.
4. The period of the function [tex]\( h \)[/tex] is half the period of the parent function.
5. The amplitude of the function [tex]\( h \)[/tex] is 3.

Thus, only these points should be considered as true descriptions of the transformations.
We appreciate your time. Please revisit us for more reliable answers to any questions you may have. We hope this was helpful. Please come back whenever you need more information or answers to your queries. Discover more at Westonci.ca. Return for the latest expert answers and updates on various topics.