【摘要】 本文通过求质量问题,引出积分概念,用点函数统一积分记号,推导出重积分化为定积分的计算方法。思路直观、新颖。更多还原

【Abstract】 Through solving the problem of quality, the paper introduces the concept of integral, unifies the symbols of integral with the help of function of position, and derives casculation method of definite integral from double integral. It possesses the advantage of being easy and direct and something new.更多还原