解:f'(x)=sinx+xcosx-sinx=xcosx令f'(x)≥0,xcosx≥0x∈[0,π],cosx≥00≤x≤π/2f(x)在[0,π/2]上单调递增,在[π/2,π]上单调递减当x=π/2时,f(x)取得最大值f(π/2)=(π/2)sin(π/2)+cos(π/2)- π/2=π/2+0-π/2=0x∈[0,π]且x≠π/2时,f(x)恒<0f(x)在[0,π]上有唯一零点x=π/2
π/2啊