The number of carbon atoms in a fossil is given by the function #y = 5100*.95^x#, where #x# represents the number of years since being discovered. What is the percent of change each year?

1 Answer
Jan 16, 2016

percentage annual change is # -5%#

Explanation:

This is a guess!
When looking at the given equation I can not help but think of compound interest. So I am going to convert this into that format.

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Within the context of financial interest:
Looking for: #P(1-x)^n#

Where P is the principle sum, #x# is the interest and n is the number of interest cycles (annual)
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Given: #y=5100(0.95)^x#

But #0.95=1-0.05# so we have

#y=5100(1-0.05)^x#

But #color(white)(.) 0.05 = 5/100#

So we have #y=5100(1-5/100)^x#

Thus the percentage change each year is #-5%#