Rajasthan BoardEnglish MediumSTD 11 ScienceMATHSModel Paper 43 Marks
Question
Show that the points (-2, 3, 5), (1, 2, 3) and (7, 0, -1) are collinear.
✓
Answer
Let A(-2, 3, 5), B (1, 2, 3) and C(7, 0, -1) be three given points. $\begin{array}{l} \text { Then } A B=\sqrt{(1+2)^2+(2-3)^2+(3-5)^2}=\sqrt{9+1+4}=\sqrt{14} \\ B C=\sqrt{(7-1)^2+(0-2)^2+(-1-3)^2}=\sqrt{36+4+16}=\sqrt{56}=2 \sqrt{14} \\ A C=\sqrt{(7+2)^2+(0-3)^2+(-1-5)^2}=\sqrt{81+9+36}=\sqrt{126}=3 \sqrt{14}\end{array}$ Now $AC = AB + BC$ Therefore,A,B,C are collinear.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.