来自纽春萍的问题
【谁能告诉我a*b=|a|*|b|cosα是怎么推理出来的?请详细说明.谢谢!】
谁能告诉我a*b=|a|*|b|cosα是怎么推理出来的?请详细说明.谢谢!
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2020-04-26 21:47
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李耀军
在欧几里得空间中,点积可以直观地定义为,这里|x|表示x的范数（长度）,θ表示两个矢量之间的角度.注意：点积的形式定义和这个定义不同；在形式定义中,a和b的夹角是通过上述等式定义的.这样,两个互相垂直的矢量的点...
2020-04-26 21:48:42
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