COMEDK20269 May 2026Morning ShiftMathematicsVector AlgebraActual

The direction ratios of the vector ( i + j ) ( j + k ) are

Options

A1, -1, 1
B0, 1, 0
C1, 0, 1
D1, 1, -1

Correct answer

A. 1, -1, 1

Step-by-step solution

Let a = i + j and b = j + k . The cross product is given by a b = vmatrix i & j & k 1 & 1 & 0 0 & 1 & 1 vmatrix . Expanding the determinant, we get: a b = i (1 - 0) - j (1 - 0) + k (1 - 0) a b = i - j + k The direction ratios of the resulting vector are the coefficients of i , j , and k , which are 1, -1, 1 . Answer: 1, -1, 1

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