- #1
Raghav Gupta
- 1,011
- 76
Homework Statement
If the vectors a and b are non-collinear and the vectors c = (x-2)a + b and d = ( 2x + 1)a - b , are collinear then x is equal to
Homework Equations
c x d = |c| |d| sin θ n where n is unit vector
The Attempt at a Solution
Since c and d are collinear there cross product magnitude would be zero.
Also cross product of c and d is abx + 3ab
Now | abx + 3ab | = 0
What would be | abx + 3ab | = ?