# Learning objectives

• Interpret and use partial derivatives as multipliers with units
• Use the master equation $\Delta z \approx (\partial z/\partial x) \Delta x + (\partial z/\partial y) \Delta y$ for $z = f(x, y)$ and small $\Delta x$ and $\Delta y$
• Make numerical approximations of partial derivatives
• Use a partial derivative in applied contexts (local linear approximation)
• Consult the main points of the lesson

Before class