①最小正周期T=2π/w=π,所以w=2,即y=sin(π/4-2x)②y=sin(π/4-2x)=-sin(2x-π/4)令t=2x-π/4,则2kπ+π/2≤t≤2kπ+3π/2为增区间,从而求出kπ+3π/8≤x≤kπ+7π/8③因为x∈[0,π/2],所以(π/4-2x)∈[-3π/4,π/4...