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AP EAMCET · Maths · Vector Algebra

If \(\vec{a}=(2 x+y) \hat{i}+3 \hat{j}+9 \hat{k}\) and \(\vec{b}=2 \hat{i}+\hat{j}-(x-y) \hat{k}\) are two collinear vectors, then \(x^3+27 y^3=\)

  1. A 1241
  2. B 1512
  3. C 1072
  4. D 1729
Verified Solution

Answer & Solution

Correct Answer

(D) 1729

Step-by-step Solution

Detailed explanation

Given: \(\vec{a}=(2 x+y) \hat{i}+3 \hat{j}+9 \hat{k}\) \(\vec{b}=2 \hat{i}+\hat{j}-(x-y) \hat{k}\) \(\because \quad \vec{a}\) and \(\vec{b}\) are co-linear vectors \(\therefore \quad \frac{2 x+y}{2}=\frac{3}{1}=\frac{9}{-(x-y)}\)…