The California emissions cap is set at 400 million metric tons of carbon dioxide equivalent in 2015 and is expected to drop by 13.2 million metric tons of carbon dioxide equivalent per year through 2020.
a. Find a linear function f giving the California emissions cap in year t, where t=0 corresponds to 2015.
b. If the same rate of decline of emissions cap was adopted through 2017, what was the emissions cap in 2017?
a) This was the way I was taught.
2020-2015=5
x= year y = tons of carbon dioxide
(0,400) (5,13.2)
= 13.2-400/5-0 = -386.8/5 = -77.36
used (0,400)
y-400=-77.36 (x-0)
y-400+400= -77.36+0
y=-77.36x+400
f(0)=-77.36(0)+400
=400
b) 2020-2017=3
77.36(3)+400=632.08
If anyone was taught to approach this problem in a different way I would like to know your method.