Graph the following points on the graphing calculator:

[tex]\[ (0, 6), \left(\frac{\pi}{2}, 7\right), (\pi, 8), \left(\frac{3\pi}{2}, 7\right), \text{ and } (2\pi, 6) \][/tex]

Explain how to use the graph to write an equation to model the gum's height. Be sure to identify the pattern of the points in your explanation, and identify the values of [tex]\( a \)[/tex] and [tex]\( k \)[/tex].



Answer :

To graph the given points and find an equation to model the points, follow these steps:

### Step 1: Plotting the Points

First, let's plot the given points on a coordinate plane. The points are:
- [tex]\( (0, 6) \)[/tex]
- [tex]\( \left(\frac{\pi}{2}, 7\right) \)[/tex]
- [tex]\( (\pi, 8) \)[/tex]
- [tex]\( \left(\frac{3\pi}{2}, 7\right) \)[/tex]
- [tex]\( (2\pi, 6) \)[/tex]

### Step 2: Observing the Pattern

Examining the plotted points, we notice the following pattern:
1. The function has a periodic nature with points repeating approximately every [tex]\(2\pi\)[/tex].
2. The values oscillate around a central value, peaking, and then dipping in a consistent pattern.

### Step 3: Identifying Parameters

Next, identify the parameters of a sinusoidal function. We consider a function of the form:
[tex]\[ y = a \sin(bx + c) + d \][/tex]

From the given points, we can make the following observations:
1. Periodicity: The function completes one cycle over [tex]\(2\pi\)[/tex], suggesting the period [tex]\(T = 2\pi\)[/tex]. The frequency [tex]\(b\)[/tex] then is
[tex]\[ b = \frac{2\pi}{T} = \frac{2\pi}{2\pi} = 1. \][/tex]

2. Amplitude: The height of the peaks and troughs about the midline of the function can be observed. From the points, the maximum value is 8, and the minimum value is 6:
[tex]\[ \text{Amplitude} = \frac{8 - 6}{2} = 1. \][/tex]
Hence, [tex]\( a = 1 \)[/tex].

3. Vertical Shift: The function oscillates around its midline. The midline can be computed as the average of the maximum and minimum values:
[tex]\[ \text{Midline} = \frac{8 + 6}{2} = 7. \][/tex]
So, [tex]\( d = 7 \)[/tex].

4. Horizontal Shift: Finally, the function appears to be a standard sinusoidal wave without a horizontal phase shift, fitting the standard sine wave well at [tex]\(x = 0\)[/tex], suggesting [tex]\( c = 0 \)[/tex].

### Step 4: Writing the Equation

Combining all these parameters, we write the equation, adjusting for the variables identified:
[tex]\[ y = a \sin(bx + c) + d \][/tex]
Substituting the values:
[tex]\[ y = 1 \sin(1x + 0) + 7 \][/tex]
or simplified,
[tex]\[ y = \sin(x) + 7 \][/tex]

### Summary
We identified the parameters [tex]\(a\)[/tex], [tex]\(b\)[/tex], [tex]\(c\)[/tex], and [tex]\(d\)[/tex] from the given periodic points and formed the sinusoidal function:
[tex]\[ y = \sin(x) + 7 \][/tex]
Here, [tex]\(a = 1\)[/tex] represents the amplitude, [tex]\(k = b = 1\)[/tex] represents the frequency, and [tex]\(d = 7\)[/tex] represents the vertical shift (midline). No horizontal shift ([tex]\(c = 0\)[/tex]) is necessary for the described points.

Graphing this function will match the given points and help us understand the pattern of the gum's height over time.