Question 180439
do exponential functions only model phenomena that grow, or can they also model phenomena that decay? Explain what is different in the form of the function in each case. 
I feel that they can grow or show decay if you have a exponential that is positive or negative
--------------------
You're right. Not an exponential, an exponent that is + or minus.
You can graph them and see them if you go to
www.padowan.dk.com/graph/
DL the free software, make the graphs.
-----------------
Explain what is different in the form of the function in each case. 
With a postive exponent, the slope is always positive and the function approaches infinity as x increases.
What a negative exponent, it's always negative and the function approaches zero as x increases.
(x is the exponent)