Answer:
Horizontal distance = 0 m and 6 m
Step-by-step explanation:
Height of a rider in a roller coaster has been defined by the equation,
y = ![\frac{1}{3}x^{2}-2x+8](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B3%7Dx%5E%7B2%7D-2x%2B8)
Here x = rider's horizontal distance from the start of the ride
i). ![y=\frac{1}{3}x^{2}-2x+8](https://tex.z-dn.net/?f=y%3D%5Cfrac%7B1%7D%7B3%7Dx%5E%7B2%7D-2x%2B8)
![=\frac{1}{3}(x^{2}-6x+24)](https://tex.z-dn.net/?f=%3D%5Cfrac%7B1%7D%7B3%7D%28x%5E%7B2%7D-6x%2B24%29)
![=\frac{1}{3}[x^{2}-2(3x)+9-9+24]](https://tex.z-dn.net/?f=%3D%5Cfrac%7B1%7D%7B3%7D%5Bx%5E%7B2%7D-2%283x%29%2B9-9%2B24%5D)
![=\frac{1}{3}[(x^{2}-2(3x)+9)+15]](https://tex.z-dn.net/?f=%3D%5Cfrac%7B1%7D%7B3%7D%5B%28x%5E%7B2%7D-2%283x%29%2B9%29%2B15%5D)
![=\frac{1}{3}[(x-3)^2+15]](https://tex.z-dn.net/?f=%3D%5Cfrac%7B1%7D%7B3%7D%5B%28x-3%29%5E2%2B15%5D)
![=\frac{1}{3}(x-3)^2+5](https://tex.z-dn.net/?f=%3D%5Cfrac%7B1%7D%7B3%7D%28x-3%29%5E2%2B5)
ii). Since, the parabolic graph for the given equation opens upwards,
Vertex of the parabola will be the lowest point of the rider on the roller coaster.
From the equation,
Vertex → (3, 5)
Therefore, minimum height of the rider will be the y-coordinate of the vertex.
Minimum height of the rider = 5 m
iii). If h = 8 m,
![8=\frac{1}{3}(x-3)^2+5](https://tex.z-dn.net/?f=8%3D%5Cfrac%7B1%7D%7B3%7D%28x-3%29%5E2%2B5)
![3=\frac{1}{3}(x-3)^2](https://tex.z-dn.net/?f=3%3D%5Cfrac%7B1%7D%7B3%7D%28x-3%29%5E2)
(x - 3)² = 9
x = 3 ± 3
x = 0, 6 m
Therefore, at 8 m height of the roller coaster, horizontal distance of the rider will be x = 0 and 6 m