Section 10.3: Applications of Growth and Decay

10.3 Outline

  1. Growth/decay formula
  2. Population growth
  3. Radioactive decay
  4. Logarithmic scales
    1. Richter number
    2. Richter scale
    3. decibel
    4. decibel formula


10.3 Essential Ideas

Exponential growth or decay can be described by the equation


where r is the annual growth/decay rate, t is the time (in years), Ao is the amount present initially (present value) and A is the future value. If r is positive, this formula models growth and if r  is negative, the formula models decay.