解；|a-c|²=a²+c²-2a.c=1+4-2[√3cos(3x/2)-sin(3x/2)]=5-4[(√3/2)cos(3x/2)-(1/2)sin(3x/2)]=5-4[cos(3x/2)cos(π/6)-sin(3x/2)sin(π/6)]=5-4cos(3x/2+π/6)因为 余弦函数值域为[-1,1]所以 |a-c|&...