Basic Exponential Functions
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First, let’s recall that for 
and 
an exponential function is any function that
is in the form

We require 
to avoid the following situation,
So, if we allowed 
we would just get the constant function, 1.
We require 
to avoid the following situation,
By requiring 
we don’t have to worry about the possibility
of square roots of negative numbers.
1. Evaluate 
,

and 
at 
.
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The point here is mostly to make
sure you can evaluate these kinds of functions.
So, here’s a quick table with the answers.
Notice that the last two rows
give exactly the same answer. If you
think about it that should make sense because,

2. Sketch the graph of 
,

and 
on the same axis system.
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3. List as some basic properties for 
.
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4. Evaluate

,

and 
at 
.
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Again, the
point of this problem is to make sure you can evaluate these kinds of
functions. Recall that in these problems
e is not a variable it is a number! In fact, 
When computing 
make sure that you do the exponentiation
BEFORE multiplying by 5.
5. Sketch the graph of 
and 
.
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As with the other “sketching”
problem there isn’t much to do here other than use the numbers we found in the
previous example to make the sketch. Here
it is,

Note that from these graphs we can see the
following important properties about 
and 
.
These properties show up with some
regularity in a Calculus course and so should be remembered.