（1） f（x）＝ab=2√2cosx+sinxcosx+2√2sinx-sinxcosx=2√2(sinx+cosx) = 2√2 × √2/2sin(x+π/4) = 2sin(x+π/4)x属于【0,π】,(x+π/4)属于【π/4,5π/4】,sin(x+π/4)属于【-√2/2,1】.所以 f（x）的值域为【...