Question

Air Pollution

The amount of nitrogen dioxide, a brown gas that impairs breathing, present in the atmosphere on a certain May day in the city of Long Beach is approximated by

A(t) = 136 / 1+0.25(t-4.5)^2 + 25 where  + 28    (0 ≤ t ≤ 11)

A(t)

is measured in pollutant standard index (PSI) and t is measured in hours, with

t = 0

corresponding to 7 a.m.† Find the intervals where A is increasing and where A is decreasing. (Enter your answers using interval notation.)

Interpret your results.

a.The pollution is increasing from 7:00 a.m. to 2:30 p.m. and decreasing after.

b. The pollution is increasing from 7:00 a.m. to 11:30 a.m. and decreasing after.   

c. The pollution is decreasing from 7:00 a.m. to 4:30 p.m. and increasing after.

d. The pollution is increasing from 7:00 a.m. to 1:30 p.m. and decreasing after.

e. The pollution is decreasing from 7:00 a.m. to 10:30 a.m. and increasing after.

Answer 1