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Câu hỏi: Trong không gian Oxyz cho $E(-1;0;2)$ và $F(2;1;-5)$. Phương trình đường thẳng EF là
A. $\dfrac{x-1}{3}=\dfrac{y}{1}=\dfrac{z+2}{-7}.$
B. $\dfrac{x+1}{3}=\dfrac{y}{1}=\dfrac{z-2}{-7}.$
C. $\dfrac{x-1}{1}=\dfrac{y}{1}=\dfrac{z+2}{-3}.$
D. $\dfrac{x+1}{1}=\dfrac{y}{1}=\dfrac{z-2}{3}.$
A. $\dfrac{x-1}{3}=\dfrac{y}{1}=\dfrac{z+2}{-7}.$
B. $\dfrac{x+1}{3}=\dfrac{y}{1}=\dfrac{z-2}{-7}.$
C. $\dfrac{x-1}{1}=\dfrac{y}{1}=\dfrac{z+2}{-3}.$
D. $\dfrac{x+1}{1}=\dfrac{y}{1}=\dfrac{z-2}{3}.$
Đường thẳng EF có vectơ chỉ phương $\overrightarrow{EF}=(3;1;-7)\Rightarrow (EF):\dfrac{x+1}{3}=\dfrac{y}{1}=\dfrac{z-2}{-7}.$
Đáp án B.