Question: USE OF DIESEL ENGINES Diesel engines are popular in cars in Europe. The percentage of new vehicles in Western Europe equipped with diesel engines is approximated by the function
f(t) = 0.3t4 - 2.58t3 + 8.11t2 - 7.71t + 23.75 (0 ≤ t ≤ 4)
Where t is measured in years, with t 0 corresponding to the beginning of 1996 .
a. Use a graphing utility to sketch the graph of f on [0, 4] × [0, 40].
b. What was the lowest percentage of new vehicles equipped with diesel engines for the period in question?