(1) X=-4,-4w+2Π/3=0;X=-1,-w+2Π/3=Π/2 方程组求得 w=Π/6X=-1,sin(-w+2Π/3)=1,A=2函数表达式f(x)=2sinΠ/6(x+4)(2)令PN=n,PQ=m,则OM=QM=PN =n,PQ=MN=m,ON=OM+MN=n+mm^2+(m+n)^2=OD^2=6矩形面积S=m*nm^2+(m+n)^2=2*m^2+n^2+2mn≥2(1+(2)^0.5)mn最大值S=3*((2)^0.5-1)