Question

If à and b are 2 unit vectors inclined to x - axis at 30° and 120°, then write the value of |a+b|
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Answer 1

Answer:

Given,

A and B are two unit vectors, therefore,

magnitude of A, and B = 1

now,

angle between A and B = 120° - 30° = 90°

We know,

|A + B| = root (A^2 + B^2 + 2AB Cos Theta)

|A + B| = root [1^2 + 1^2 + 2 (1)(1)cos (90)]

|A + B| = root (2 + 2 × 0) = root 2