Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NDA2013MathematicsVector AlgebraActual

If the angle between the vectors i -m j and j + k is 3 , then what is the value of m ?

Options

  1. A0
  2. B2
  3. C–2
  4. DNone of the above

Correct answer

D. None of the above

Step-by-step solution

aligned Let, A & = i -m j and B = j + k ~A ~B & =| A | | B | ( ) aligned aligned ( i -m j ) ( j + k ) & =| i -m j | | j + k | ( 3 ) -m & = | 1+m^2 | | 1^2+1^2 | 1 2 or, - 2 m & = 1+m^2 aligned Squaring both sides, we get aligned 2 m^2 & =1+m^2 m^2=1 m & = 1 aligned

Practice Vector Algebra on Quantrex Academy →

More from Vector Algebra

Passage: Let a b = c and b c = a . Question: Consider the following statements : I. ( a b ) c +( b c ) a =( c a ) b II. ( a b ) ( b c ) b =1 Which of the statements given above is/ 2026Passage: Let a , b , c , a + b , b + c , a + b + c be unit vectors. Question: What is the angle between a and b ? 2026Passage: Let a , b , c be unit vectors. Further, a is perpendicular to b ; c makes an angle 3 with both a and b ; and c =p a +q b +r( a b ) . Question: What is the value of r^2 ? 2026Passage: Let a , b , c , a + b , b + c , a + b + c be unit vectors. Question: What is the angle between a and c ? 2026Passage: Let a b = c and b c = a . Question: Consider the following statements : I. a , b , c are orthogonal in pairs. II. a , b , c are unit vectors. Which of the statements given 2026Passage: Let a , b , c be unit vectors. Further, a is perpendicular to b ; c makes an angle 3 with both a and b ; and c =p a +q b +r( a b ) . Question: What is the value of (p+q) ? 2026What is the area of the parallelogram whose sides are represented by the vectors i + 2 j + 3 k and 2 i + j + 2 k ? 2025Let p = a - b , q = a + b . If | a | = | b | = 2 and a b = 2 , then what is the value of | p q | ? 2025 Full Vector Algebra list All NDA PYQs