A track has a height that is a function of horizontal position x, given by h(x) = x^3 + 4x^2 − 44x + 16.
Find all the positions on the track where a marble will remain where it is placed. What kind of equilibrium exists at each of these positions? (Enter your answers from smallest to largest.)
The answers are -5.39 and 2.72. I'm not sure where to start this problem. I thought that I would have to take h(x)'s derivative and set it equal to zero, but it did not work. Any help is appreciated.
So you want to find the minimum heights...
h'=0=3x^2+8x-44
use the quadratic equation to solve for the x positions.
x=(-8+-sqrt(64+4*3*44))/6=-4/3 +-4.05
which is your answers.