# Math Help - Understanding Functions

1. ## Understanding Functions

Why is the following true:

f(a)f(b) = 2^ab = 2^a+b

2. Originally Posted by juliak
Why is the following true:

f(a)f(b) = 2^ab = 2^a+b
are you sure it isn't ...

if $f(x) = 2^x$ ...

$f(a) \cdot f(b) = 2^a \cdot 2^b = 2^{a+b}$

because, in general, $2^{ab} \ne 2^{a+b}$

3. In general, they aren't equal.
Do you mean $(c^m)(c^n) = c^{m+n}$?