To find \( f(2) \) using the function rule \( f(x) = 12^x - 4 \), we substitute \( x = 2 \) into the function:
\[ f(2) = 12^2 - 4 \]
Now, we calculate \( 12^2 \):
\[ 12^2 = 144 \]
Now, substituting back, we have:
\[ f(2) = 144 - 4 = 140 \]
Thus,
\[ f(2) = 140 \]