【摘要】 本文讨论在某一点(x0,y0)关于 x(或y的偏导数存在后对充分接近)y0或 , ( x0 的)y1(或x1)函数f (x, y1(或)f (x1, y的)), y1是否存在x0或 ( y0)连续的条件作出分析,并给出有条件的定理1 , 并用其证明了一个二元函数的可微的充分条件。更多还原

【Abstract】 This paper discusses the existence of partial derivative of x(or y) about a point (x0, y0), and analyzes conditions of continuance of x0(or y0) about function of y1(or x1)-f(x, y,) (or f(x, y) ), and puts forward a conditioned theorem, by which differential sufficient condition of a binary function can be demonstrated.更多还原