Graph 1: Domain = 2 <= x < 12
Graph 1: Range = {2,4}
Graph 2: Domain = 3 <= x <= 10
Graph 2: Range = -6 <= y <= 4
Graph 3: Domain = 4 < x < 11
Graph 4: Range = -6 <= y < 2
I think the largest time interval over which the actual price per watt of a solar panel was an increasing function of time is : 2004 to 2006
As it gives data %growth over previous year
from 2003 to 2004 it was -5.7% but from 2004 to 2005 6.7 % from 2005 to 2006 it is 97 % and from there it once again decline
hope this helps
