Find the derivative of the function. \[ y=8^{4 x-9} \] \( y^{\prime}=\square \)

To find the derivative of the function \( y = 8^{4x - 9} \), we can use the chain rule and the property of exponential functions. The derivative of \( a^u \) is given by \( a^u \ln(a) \cdot u' \), where \( u \) is a function of \( x \). Here, let \( u = 4x - 9 \). Then \( u' = 4 \). Now, applying the derivative formula: \[ y' = 8^{4x - 9} \ln(8) \cdot (4) \] Thus, we can write: \[ y' = 4 \cdot 8^{4x - 9} \ln(8) \] Therefore, the derivative is: \[ y' = 4 \cdot 8^{4x - 9} \ln(8). \]