Question

You end up having to get some ear-infection medication for your pet iguana. The vet said that the initial 20 mgs of medication would lose 10% of its effectiveness every day. Come up with a table, equation, and graph representing this scenario.

Answer 1

See attached graph

Explanation:

The attached table and graph show the effective dose as a function of days, x, starting at 20 mg and declining by 10% each day.

The equation that provides this information is f(x) = (20 mg)*(1-0.10)^x, where x is days since the original 20 mg dose. The factor (1 - 0.10) [or 90%] reduces the original amount x times (3 days would be (1-0.10)^3, or (1-0.10)*(1-0.10)*(1-0.10) = 14.58 grams effective dose from 20 grams original dose.