If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

## Algebra 1

### Unit 12: Lesson 5

Exponential growth & decay

# Writing functions with exponential decay

## Problem

Carbon-14 is an element that loses about 10, percent of its mass every millennium (i.e., 1000 years). A sample of Carbon-14 has 600 grams.
Write a function that gives the sample's mass in grams, S, left parenthesis, t, right parenthesis, t millennia from today.
S, left parenthesis, t, right parenthesis, equals
Stuck?
Stuck?