作业帮已知向量a=(cos3/2x,sin3/2x),向量b=(cosx/2,-sinx/2),且x属于[0,pai/2](1):用x表示向量a乘以向量b及|向量a+向量b|,并化简 (2)求函数f(x)=向量a乘以向量b-4|向量a+向量b|的最小值`````````请尽快帮忙
来源：学生作业帮助网 编辑：作业帮 时间：2024/07/12 23:19:41
:用x表示向量a乘以向量b及|向量a+向量b|,并化简 (2)求函数f(x)=向量a乘以向量b-4|向量a+向量b|的最小值`````````请尽快帮忙](/uploads/image/z/2623147-43-7.jpg?t=%E5%B7%B2%E7%9F%A5%E5%90%91%E9%87%8Fa%3D%28cos3%2F2x%2Csin3%2F2x%29%2C%E5%90%91%E9%87%8Fb%3D%28cosx%2F2%2C-sinx%2F2%29%2C%E4%B8%94x%E5%B1%9E%E4%BA%8E%5B0%2Cpai%2F2%5D%281%29%3A%E7%94%A8x%E8%A1%A8%E7%A4%BA%E5%90%91%E9%87%8Fa%E4%B9%98%E4%BB%A5%E5%90%91%E9%87%8Fb%E5%8F%8A%7C%E5%90%91%E9%87%8Fa%2B%E5%90%91%E9%87%8Fb%7C%2C%E5%B9%B6%E5%8C%96%E7%AE%80+%282%29%E6%B1%82%E5%87%BD%E6%95%B0f%28x%29%3D%E5%90%91%E9%87%8Fa%E4%B9%98%E4%BB%A5%E5%90%91%E9%87%8Fb-4%7C%E5%90%91%E9%87%8Fa%2B%E5%90%91%E9%87%8Fb%7C%E7%9A%84%E6%9C%80%E5%B0%8F%E5%80%BC%60%60%60%60%60%60%60%60%60%E8%AF%B7%E5%B0%BD%E5%BF%AB%E5%B8%AE%E5%BF%99)
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已知向量a=(cos3/2x,sin3/2x),向量b=(cosx/2,-sinx/2),且x属于[0,pai/2](1):用x表示向量a乘以向量b及|向量a+向量b|,并化简 (2)求函数f(x)=向量a乘以向量b-4|向量a+向量b|的最小值`````````请尽快帮忙
已知向量a=(cos3/2x,sin3/2x),向量b=(cosx/2,-sinx/2),且x属于[0,pai/2]
(1):用x表示向量a乘以向量b及|向量a+向量b|,并化简 (2)求函数f(x)=向量a乘以向量b-4|向量a+向量b|的最小值`````````请尽快帮忙
已知向量a=(cos3/2x,sin3/2x),向量b=(cosx/2,-sinx/2),且x属于[0,pai/2](1):用x表示向量a乘以向量b及|向量a+向量b|,并化简 (2)求函数f(x)=向量a乘以向量b-4|向量a+向量b|的最小值`````````请尽快帮忙
a*b=cos3/2x*cosx/2-sinx/2*sin3/2x=cos（3/2x+x/2）=cos(2x)
|向量a+向量b|=|(cos3/2x+cosx/2,sin3/2x-sinx/2)|
把整个平方一下,再给整个加个根号
后面的题和上一题解出的值有关,你算吧