The angle between the vectors (i+j) and (j+k) is
Options
(a) 90⁰
(b) 60⁰
(c) 30⁰
(d) 45⁰
Correct Answer:
60⁰
Explanation:
A = i + j, B = j + k
A . B = |A| |B| cos θ
where θ is the angle between two vectors A and B.
.·. A.B = (i + j).(j + k) = 1
|A| = √(1² + 1²) = √2,
|B| = √(1² + 1²) = √2
.·. cos θ = A.B / |A| |B| = 1/(√2×√2) = 1/2
θ = cos⁻¹ (1/2) = 60⁰