The volume problem in calculus

<正>Everyone knows that the area of the base of solid is A,and the height is h,then the volume of it is V=A·h.It's an experience on math class in primer or middle school.Although you have an intuitive idea of what volume means,however,you can make this idea precise by using calculus to give an exact definition of volume.You will know what the concept of volume is in the calculus.