# Let f(x)=3^x, what is the value of f(4)?

$f \left(4\right) = {3}^{4} = 3 \cdot 3 \cdot 3 \cdot 3 = 9 \cdot 9 = 81$
$f \left(4\right) = {3}^{4} = 3 \cdot 3 \cdot 3 \cdot 3 = 9 \cdot 9 = 81$