10答案:解:(1)分割:把区间[0,1]等分成n个小区间(i=1,2,...,n),其长度为Δx=,把梯形分成n个小梯形,其面积记为ΔSi(i=1,2,...,n).
(2)近似代替:用小矩形面积近似代替小梯形面积.
=
=(i-1)(i=1,2,...,n).
(3)作和:
=[1+2+...+(n-1)]
=.
(4)逼近:,
当n→∞时,S→,
故所求面积约等于.