讨论三元二次曲面是封闭图形的条件及封闭图形所围图形体积的计算,并将结果的形式推广到二元和一元二次方程所围封闭图形的判定上和面积或长度的计算上.
This paper deals with the condition of surface of ternary function is closed surface and volume calculation of enclosed graphic by quadratic surface. The result has been generalized to the case of binary function and simple function.