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MHT CET202613 April 2026Evening ShiftMathematicsVector AlgebraActual

If a = i + j and b = i - k , then the point of intersection of the lines r a = b a and r b = a b is

Options

  1. A(2, 1, -1)
  2. B(2, -1, 1)
  3. C(0, 1, 1)
  4. D(0, -1, 1)

Correct answer

A. (2, 1, -1)

Step-by-step solution

The given equations of the lines are r a = b a and r b = a b . From the first equation, we can write: r a - b a = 0 ( r - b ) a = 0 This implies that the vector r - b is parallel to a . Thus, r = b + a for some scalar . Similarly, from the second equation: r b - a b = 0 ( r - a ) b = 0 This implies that the vector r - a is parallel to b . Thus, r = a + b for some scalar . At the point of intersection, the position vector r must satisfy both conditions: b + a = a + b ( - 1) a + (1 - ) b = 0 Since a = i + j and b = i

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