Find a value a greater than 0 so that the graph of the exponential function f(x) =a^x contains he point (2,1/16)

The exponential function is $\"\"$ .

He contain point is $\"\"$ .

Substitute $\"\"$ in $\"\"$ to get exponential function.

$\"\"$

The exponential function is $\"\"$ .

Graph the function $\"\"$ .

$\"\"$