Exponentials
Growth & Decay
Application 4
A certain chemical compound has a half-life of 14 days. Currently there is 45 mg of the compound. Write an equation to model the half-life of this compound.
Step 1. Determine the initial value. The compound starts with 45 mg.
Step 2. Write the rate as a decay factor. The chemical has a half-life.
for every 14 days
Step 3. Alter the exponent to include the half-life of 14 days. This input is going up by 14; therefore take the 14th root of ½ to simplify the expression.
Step 4. Write the equation.