1. **State the problem:** We need to write an equation for the height $y$ of Aaron's Ferris wheel car as a function of time $t$ in minutes.
2. **Analyze the graph:** The height oscillates between a minimum of about 15 feet and a maximum of about 395 feet.
3. **Find the amplitude:** Amplitude $A$ is half the distance between max and min heights:
$$A = \frac{395 - 15}{2} = \frac{380}{2} = 190$$
4. **Find the midline (vertical shift):** Midline $D$ is the average of max and min heights:
$$D = \frac{395 + 15}{2} = \frac{410}{2} = 205$$
5. **Determine the period:** The graph completes two full cycles in 20 minutes, so one period $T$ is:
$$T = \frac{20}{2} = 10$$
6. **Find the angular frequency:**
$$\omega = \frac{2\pi}{T} = \frac{2\pi}{10} = \frac{\pi}{5}$$
7. **Determine phase shift:** The maximum height occurs at $t=9$ minutes. The cosine function has its maximum at $t=0$, so phase shift $\phi$ satisfies:
$$\omega t - \phi = 0 \Rightarrow \phi = \omega \times 9 = \frac{\pi}{5} \times 9 = \frac{9\pi}{5}$$
8. **Write the equation:** Using cosine (since max at $t=9$), the height is:
$$y = A \cos\left(\omega t - \phi\right) + D = 190 \cos\left(\frac{\pi}{5} t - \frac{9\pi}{5}\right) + 205$$
**Final answer:**
$$y = 190 \cos\left(\frac{\pi}{5} t - \frac{9\pi}{5}\right) + 205$$
Ferris Wheel Height Ec58Ee
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