If $f(x)=4^{x}$, find $f(1)$ and $f(-1)$

Step 1 ：The function is defined as \(f(x)=4^{x}\).

Step 2 ：To find \(f(1)\), we substitute \(x=1\) into the function, giving us \(4^{1} = 4\).

Step 3 ：To find \(f(-1)\), we substitute \(x=-1\) into the function, giving us \(4^{-1} = 0.25\).

Step 4 ：Final Answer: \(f(1) = \boxed{4}\) and \(f(-1) = \boxed{0.25}\)