设f(x)=sinx,x∈[0,π/2） f(x)= 1,x∈[π/2,2].则f(x)dx在0到2上的积分为

∫上2下0；f(x)dx
=∫上2下π/2；f(x)dx+∫上π/2下0；f(x)dx
=∫上2下π/2；1dx+∫上π/2下0；sinxdx
=x│上2下π/2-cosx│上π/2下0
=（2-π/2）-（0-1）
=3-π/2