Module 11 :   Partial derivatives, Chain rules,  Implicit differentiation, Gradient, Directional derivatives
Lecture 31 :  Partial derivatives  [Section 31.1]
 
 
                                                               Figure 1. Partial Derivative
31.1.2 Definition:
 

Let be an interior point and . The partial derivative of with respect to at , denoted by or , is the limit

if it exists. Likewise, the partial derivative of with respect to at , denoted by or , is the limit

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