y=sinx-cosx=√2·sin(x-π/4)
∵函数y=sinx的单调区是[2kπ-π/2,2kπ+π/2]
∴2kπ-π/2≤x-π/4≤2kπ+π/2
即2kπ-π/4≤x≤2kπ+3π/4
又 x∈[0,π]
∴ 0≤x≤3π/4
故函数y=sinx-cosx(x∈[0,π])的单调递增区间是[0,3π/4]
y=sinx-cosx=√2·sin(x-π/4)
∵函数y=sinx的单调区是[2kπ-π/2,2kπ+π/2]
∴2kπ-π/2≤x-π/4≤2kπ+π/2
即2kπ-π/4≤x≤2kπ+3π/4
又 x∈[0,π]
∴ 0≤x≤3π/4
故函数y=sinx-cosx(x∈[0,π])的单调递增区间是[0,3π/4]