Answer :
Correct question:
A motorcycle stunt rider jumped across the Snake River. The path of his motorcycle was given
approximately by the function H(t) = - 0.0004.x2 + 2.582 + 700, where H is measured in
feet above the river and is the horizontal distance from his launch ramp.
How high above the river was the launch ramp?
What was the rider's maximum height above the river, and how far was the ramp when he reached maximum height?
Answer:
A) 700 feet ; 4866.7025 feet above the river
3227.5 Feets from the ramp
Step-by-step explanation:
Given the Height function:
H(t) = 0.0004x^2 + 2.582x + 700
H = height in feet above the river
x = horizontal distance from launch ramp.
How high above the river was the launch ramp?
H(t) = - 0.0004x^2 + 2.582x + 700
To find height of launch ramp above the river, we set the horizontal distance to 0, because at this point, the motorcycle stunt rider is on the launch ramp and thus the value of H when x = 0 should give the height of the launch ramp above the river.
At x = 0
Height (H) =
- 0.0004(0)^2 + 2.582(0)+ 700
0 + 0 + 700 = 700 Feets
B) Maximum height abive the river and how far the rider is from the ramp when maximum height is reached :
Taking the derivative of H with respect to x
dH'/dx = 2*-(0.0004)x^(2-1) + 2.582x^(1-1) + 0
dH'/dx = 2*-(0.0004)x^(1) + 2.582x^(0) + 0
dH'/dx = - 0.0008x + 2.582
Set dH'/dx = 0 and find x:
0 = - 0.0008x + 2.582
-2.582 = - 0.0008x
x = 2.582 / 0.0008
x = 3227.5 feets
To get vertical position at x = 0
Height (H) =
- 0.0004(3227.5)^2 + 2.582(3227.5)+ 700
- 4166.7025 + 8333.405 + 700
= 4866.7025 feet
4866.7025 feet above the river
3227.5 Feets from the ramp
Using quadratic function concepts, it is found that:
- The launch ramp was 700 feet above the river.
- The maximum height is of 4866.7 feet.
- The ramp was 3227.5 feet along when he reached maximum height.
The height after x seconds is given by the following equation:
[tex]H(x) = -0.0004x^2 + 2.582x + 700[/tex]
Which is a quadratic equation with coefficients [tex]a = -0.0004, b = 2.582, c = 700[/tex]
The height of the ramp is the initial height, which is:
[tex]H(0) = -0.0004(0)^2 + 2.582(0) + 700 = 700[/tex]
Thus, the launch ramp was 700 feet above the river.
The maximum height is the h-value of the vertex, given by:
[tex]h_{MAX} = -\frac{\Delta}{4a} = -\frac{b^2 - 4ac}{4a}[/tex]
Then, substituting the coefficients:
[tex]h_{MAX} = -\frac{(2.582)^2 - 4(-0.0004)(700)}{4(-0.0004)} = 4866.7[/tex]
The maximum height is of 4866.7 feet.
The horizontal distance is the x-value of the vertex, given by:
[tex]x_V = -\frac{b}{2a} = -\frac{2.582}{2(-0.0004)} = 3227.5[/tex]
The ramp was 3227.5 feet along when he reached maximum height.
A similar problem is given at https://brainly.com/question/24705734