Exponential Growth Decay

Document Sample
Exponential Growth Decay Powered By Docstoc
					  Exponential Growth & Decay
 Exponential Growth     Exponential Decay

___________________   ___________________
___________________   ___________________
___________________   ___________________
___________________   ___________________
___________________   ___________________
___________________   ___________________
Exponential Growth               Exponential Decay

   y = C(1 + r)t                      y = C(1 - r)t

          rate MUST be expressed as a decimal
  Exponential Growth Problem
A rancher begins his herd of cattle with 15.
  The herd grows by 30% each year.

Write a MODEL (the equation, uncompleted)
 for the size of the herd during the first
 several years.

 Now determine how many cattle
the rancher will have after 4 years.
        Compound Interest
               y = P (1 + r)t

You deposit $500 into a savings account.
 The interest rate pays 8% yearly. Find the
 account balance after 6 years.
Newly hatched catfish weigh 0.06 grams. In
   the first 6 weeks, the weight increases
     10% per DAY. At the end of the six
          weeks, what is the weight?
There is a population of 20 mice. The
 population triples in a year. Find the
        population after 5 years.
Exponential Decay Problem
You buy a used car for $7,000. The car
depreciates at a rate of 6% per year. Find
  the value of the car after the 5 years.
            Factor vs. Rate
• Growth factor     • Decay factor

• Growth rate       • Decay rate