ExamBro
ExamBro
AP EAMCET · Maths · Three Dimensional Geometry

If the four points \((6,2,4),(1,3,5),(1,-2,3)\) and \((6, \mathrm{k}, 2)\) are coplanar, then \(\mathrm{k}=\)

  1. A -5
  2. B 4
  3. C -3
  4. D 1
Verified Solution

Answer & Solution

Correct Answer

(C) -3

Step-by-step Solution

Detailed explanation

\(\vec{AB} = (1-6, 3-2, 5-4) = (-5, 1, 1)\) \(\vec{AC} = (1-6, -2-2, 3-4) = (-5, -4, -1)\) \(\vec{AD} = (6-6, k-2, 2-4) = (0, k-2, -2)\) \(\begin{vmatrix} -5 & 1 & 1 \\ -5 & -4 & -1 \\ 0 & k-2 & -2 \end{vmatrix} = 0\) \(-5(8+k-2) - 1(10-0) + 1(-5(k-2)-0) = 0\)…