Question

Points (–2, 4, 7), (3, –6, –8) and (1, –2, –2) are
[AI CBSE 1982]

• A. Collinear
• B. Vertices of an equilateral triangle
• C. Vertices of an isosceles triangle
• D. None of these

Answer 1

The correct option is A

Collinear

Here, $\frac{(3-(-2\left)\right)}{1-3}=\frac{-6-4}{-2-(-6)}=\frac{-8-7}{-2-(-8)}$
$\Rightarrow -\frac{5}{2}=-\frac{5}{2}=-\frac{5}{2}.$ Obviously, points are collinear.