To find the first derivative \( f^{\prime}(x) \) of the function \( f(x) = (x^2 + 4)^6 \), we apply the chain rule. The result is:
\[
f^{\prime}(x) = 12x(x^2 + 4)^5
\]
Step 2: Find the Second Derivative
Next, we differentiate the first derivative \( f^{\prime}(x) \) to obtain the second derivative \( f^{\prime \prime}(x) \). The calculation yields:
\[
f^{\prime \prime}(x) = 120x^2(x^2 + 4)^4 + 12(x^2 + 4)^5
\]
Final Answer
Thus, the second derivative of the function is:
\[
\boxed{f^{\prime \prime}(x) = 120x^2(x^2 + 4)^4 + 12(x^2 + 4)^5}
\]