Three vectors are expressed as a =4 i - j , b =-3 i +2 j and c =- k . The unit vector along the direction of sum of these vectors is

Step-by-step solution

The resultant vector is found by summing the components: R = (4 i - j ) + (-3 i + 2 j ) + (- k ) = (1) i + (1) j + (-1) k The magnitude is | R | = 1^2 + 1^2 + (-1)^2 = 3 The unit vector is therefore R = R | R | = 1 3 i + 1 3 j - 1 3 k This corresponds to option A .