求与向量a=(3,-1)和b=(1,3)的夹角均相等,且模为2的向量的坐标
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a的斜率k1=-1/3,b的斜率k2=3,所求向量的斜率为k|(k-k1)/(1+k*k1)|=|(k2-k)/(1+k*k2)|解得k=-2,1/2所求向量是(-2√5/5,4√5/5),(2√5/5,-4√5/5),(4√5/5,2√5/5),(-4√5/5,-2√5/5)
求与向量a=(3,-1)和b=(1,3)的夹角均相等,且模为2的向量的坐标
a的斜率k1=-1/3,b的斜率k2=3,所求向量的斜率为k|(k-k1)/(1+k*k1)|=|(k2-k)/(1+k*k2)|解得k=-2,1/2所求向量是(-2√5/5,4√5/5),(2√5/5,-4√5/5),(4√5/5,2√5/5),(-4√5/5,-2√5/5)