Simplify $(4a^2)^3$.
I need to simplify this expression by applying the exponent and power rules. First, I can use the power of a power rule, which says that $(a^b)^c = a^{bc}$. So, $(4a^2)^3 = 4^3a^{2 \cdot 3}$. Then, I can evaluate $4^3 = 4 \cdot 4 \cdot 4 = 64$. And I can simplify $a^{2 \cdot 3} = a^6$. So, the final answer is $64a^6$. 