※ 引述《dreamroyc ()》之铭言： : Please find a unit vector that is orthogonal to both : vectors u=i-4j+k and v=2i+3j. : 翻了参考书，没看到相关的例题，也没有任何头绪。 : 烦请各位指点一下... 跟 u = i - 4j + k 与 v = 2i + 3j 正交的向量为 | i j k | | | (u) cross (v) = | 1 -4 1 | | | | 2 3 0 | |-4 1 | | 1 1 | | 1 -4 | = (i)| | - (j)| | + (k)| | | 3 0 | | 2 0 | | 2 3 | = (i)(-3) - (j)(-2) + (k)(3 + 8) = (-3)(i) + (2)(j) + (11)(k) 然後取单位向量 (-3)(i) + (2)(j) + (11)(k) ----------------------------- √((-3)^2 + 2^2 + 11^2) -3 2 11 = (-------)(i) + (-------)(j) + (-------)(k) √134 √134 √134 --

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