Sinusoidal Parameters 78985E
1. **State the problem:** We are given a sinusoidal function of the form $$y = a \sin\bigl(b(x - c)\bigr) + d$$ and a graph description. We want to identify the parameters $a$, $b$, $c$, and $d$ based on the graph.
2. **Recall the formula and parameters:**
- $a$ is the amplitude (half the distance between maximum and minimum values).
- $b$ affects the period of the sine wave, with period $$T = \frac{2\pi}{b}$$.
- $c$ is the horizontal shift (phase shift).
- $d$ is the vertical shift (midline of the wave).
3. **Analyze the graph:**
- The maximum value is approximately 6.
- The minimum value is approximately -2.
- The vertical shift $d$ is the midpoint between max and min:
$$d = \frac{6 + (-2)}{2} = \frac{4}{2} = 2$$
- The amplitude $a$ is half the distance between max and min:
$$a = \frac{6 - (-2)}{2} = \frac{8}{2} = 4$$
4. **Determine the period and $b$:**
- The period $T$ is about $\pi$ (the wave repeats every $\pi$ units).
- Using the period formula:
$$T = \frac{2\pi}{b} \implies b = \frac{2\pi}{T} = \frac{2\pi}{\pi} = 2$$
5. **Determine the horizontal shift $c$:**
- The sine function normally starts at zero at $x=0$.
- The graph shows a shift to the right by $c$ units.
- Since the wave starts near $x = \frac{\pi}{2}$ (where sine normally peaks), and the sine function peaks at $\frac{\pi}{2}$ without shift, the phase shift $c$ is approximately 0.
6. **Final function:**
$$y = 4 \sin\bigl(2(x - 0)\bigr) + 2 = 4 \sin(2x) + 2$$
This matches the graph's amplitude, period, and vertical shift.
**Answer:** $$\boxed{y = 4 \sin(2x) + 2}$$