Topics covered by the second midterm exam:

• Partial derivatives (sect. 14.3.)
• The chain rule (sect. 14.4.)
• Directional derivatives and gradient (sect 14.5.)
• Tangent plane and diffeerential (sect. 14.6)
• Extreme values and saddle point  (funct.  of  two variables )(sect 14.7)
• Extreme values and saddle point  (funct.  of  three variables )
• Lagrange multipliers (sect. 14.8.)
• Double integral (sect. 15.1.)
• Double integral in polar coordinates (sect. 15.3.)