Harvesting:
x.= a1x - a2x2 - h; a1 > 0, a2 > 0, h>0
1. |x| = tons and |x.| = tons/years What are the dimensions of a1, a2, and h?
2. Use the quadratic formula to show that the phase diagrams (x. vs. x)have no intercepts:
If a12/4a2
If h = a12/4a2 what is intercept?
3. If h < a12/4a2 , x. vs. x will have 2 intercepts, what are the signs ( + or - )?
4. Plot x.vs. x for h = a12/4a2, h < a12/4a2 , h > a12/4a2
What is the significance of h = a12/4a2 with respect to the phase diagrams?
5. Normalize and non-dimensionalize the harvesting equation using the variable transformation:
h→ h*
t→ t*
x→ x*
for h= h*h-; t= t*t-; x= x*x-, where t-, x-, h- are constants.
then use h-= a12/2a2; t- =2/a1; x-= a12/2a2 to simplify the equation
6. If h2/4a2 what is the magnitude for h*? What is the equilibrium value for x*?
7. How do the values in number 6 relate to the h = a12/4a2 phase diagram?