1. Chlorine is frequently used to disinfect swimming pools. The chlorine concentration should remain between 1.5 and 2.5 parts per million (ppm) for safe swimming. After a warm, sunny day only 80% of the chlorine may remain in the water, with the other 20% dissipating into the air or combining with chemicals in the water. Let f(t)=3(0.8)^t model the concentration of chlorine in parts per million after t days.

What is the initial concentration of chlorine in the pool?

Question

1.  Chlorine is frequently used to disinfect swimming pools.  The chlorine concentration should remain between 1.5 and 2.5 parts per million (ppm) for safe swimming.  After a warm, sunny day only 80% of the chlorine may remain in the water, with the other 20% dissipating into the air or combining with chemicals in the water.  Let f(t)=3(0.8)^t   model the concentration of chlorine in parts per million after t days.

What is the initial concentration of chlorine in the pool?

anonymous · Answer

unless i miss my guess "initial concentration" means what you start with, i.e. what you get when t = 0.  when t = 0 you have 3 ppm, the number in front of the base.