Math exponential decay

Answer 1

Definition: Exponential decay refers to an amount of substance decreasing exponentially. Exponential decay is a type of exponential function where instead of having a variable in the base of the function, it is in the exponent.

The best known examples of exponential decay involves radioactive materials such as uranium or plutonium. Another example, if inflation is making prices rise by 3% per year, then the value of a $1 bill is falling or exponentially decaying, by 3% per year.

new value=initial value x (1-r)^t where t =time and r =rate/100

Example: China's One-Child Policy was implemented in 1978 with a goal of reducing China's population to 700 million by 2050. China's 2000 population is about 1.2 billion. Suppose that China's population declines at a rate of 0.5% per year. Will this rate be sufficient to meet the original goal?

plug in the numbers for the equation: new value=1.2billionx(1-0.005)^50

new value=0.93 billion

hope this helps! Please check out more exponential decay examples in the links! =)