解析：f（x）＝sinx－cosx＋x＋1则f'(x)＝cosx＋sinx＋1＝√2（√2/2cosx＋√2/2sinx）＋1＝√2（sinπ/4cosx＋cosπ/4sinx）＋1＝√2sin（x＋π/4）＋1.令0＜x＋π/4＜π/2且3π/2＜x＜2π得－π/4＜x＜π/4且5π/4...