In order to understand the definition of differentiable of binary function more intuitively and comprehensively, by means of geometric method, the definition of differentiable of binary function is explained in detail , and the geometric meaning of total differential of binary function is given. The relationship between the total differential of binary function and the differential of unary function is revealed.
王素娟. 对二元函数可微定义的若干注释 [J]. 兴发pt登录学报, 2018, 35(9): 115-118. WANG Su-juan. Notes on The Definition of Differentiable of Binary Function . Journal of Jilin Institute of Chemical Technology, 2018, 35(9): 115-118.