已知向量a=(cos3/2x,sin3/2x),b=(cos1/2x,-sin1/2x),且x∈[0,派/2],若f(x)=a·b-2K|a+b|的最小值是-3/2,求K的值.谢咯..

楼上解法正确,过程有点错误：已知向量a=(cos3/2x,sin3/2x),b=(cos1/2x,-sin1/2x),且x∈[0,派/2],若f(x)=ab-2K|a+b|的最小值是-3/2,求K的值.a·b =[cos(3/2)x·cos(1/2)x + sin(3/2)x·(-sin1/2x) =[cos(3/2)x·cos(1...