• Oct 26th 2012, 11:37 PM
VARSOFFON
Clovis is standing at the edge of a cliff, which slopes 6 feet downward from him for every 1 horizontal foot. He launches a small model rocket from where he is standing. With the origin of the coordinate system located where he is standing, and the x-axis extending horizontally, the path of the rocket is described by the formula y = −3x^2 + 120x.

(a) Give a function h = f(x)
relating the height h of the rocket above the sloping ground to its x-coordinate.
-3x^2 + 126x
(b) Find the maximum height of the rocket above the sloping ground. What is its x-coordinate when it is at its maximum height?
1332, 121
(c) Clovis measures its height h of the rocket above the sloping ground while it is going up. Give a function x = g(h)
relating the x-coordinate of the rocket to h.

How would I go about solving for c?
• Oct 27th 2012, 12:14 AM
chiro
Hey VARSOFFON.

With regards to part c, you want to find the region where the rocket is increasing which means that this will be from where it time = 0 to the time of the maximum.

Hint: Consider completing the square and the take the right branch of the square root.
• Oct 27th 2012, 12:15 AM
VARSOFFON
Ohh okay thank you very much!
• Oct 27th 2012, 12:16 AM
MarkFL
$h(x)=-3x^2+126x$ where $0\le x\le21$
$3x^2-126x+h=0$