Use the Chain Rule to find \( \frac{d z}{d t} \), where \( z=3 x \cos y, x=t^{5} \), and \( y=6 t^{4} \). \( \frac{\partial z}{\partial x}=\square \) (Type an expression using \( x \) and \( y \) as the variables.)

To find \( \frac{\partial z}{\partial x} \), we first need to express \( z \) in terms of \( x \) and \( y \). Given \( z = 3x \cos y \), we can directly take the partial derivative with respect to \( x \). Calculating this, we get: \[ \frac{\partial z}{\partial x} = 3 \cos y \] So, it's expressed as: \[ \frac{\partial z}{\partial x} = 3 \cos y \]