ExamBro
ExamBro
TS EAMCET · Maths · Vector Algebra

Consider the four points \(A(1,-2,-1)\), \(B(4,0,-3), C(1,2,-1)\) and \(D(2,-4,-5)\) in space. If \(\mathbf{b}=\mathbf{A B}, \mathbf{c}=\mathbf{A C}\) and \(\mathbf{d}=\mathbf{A D}\), then

  1. A 40
  2. B -40
  3. C 20
  4. D -20
Verified Solution

Answer & Solution

Correct Answer

(D) -20

Step-by-step Solution

Detailed explanation

\(\mathbf{O A}=\hat{\mathbf{i}}-2 \hat{\mathbf{j}}-\hat{\mathbf{k}}, \mathbf{O B}=4 \hat{\mathbf{i}}+0 \hat{\mathbf{j}}-3 \hat{\mathbf{k}}\) \(\mathbf{O C}=\hat{\mathbf{i}}+\hat{\mathbf{j}}-\hat{\mathbf{k}}, \mathbf{O D}=\hat{\mathbf{i}}-4 \hat{\mathbf{j}}-5 \hat{\mathbf{k}}\)…