Find the angle between the vectors and when i. and ii. and iii. and

Question

Philoid · Accepted Answer

i) and

|| =

We know that ,

⇒

⇒ (3 + 4 + 3) = 14cosθ

⇒ cosθ = 10/14

⇒ cosθ = 5/7

⇒ θ = cos ^{- 1}(5/7)

Ans: θ = cos ^{- 1}(5/7)

ii) and

|| =

We know that ,

⇒

⇒ (6 - 2 + 8) = √336 cosθ

⇒ cosθ = 12/√336

⇒ cosθ = √(144/336)

⇒ θ = cos ^{- 1}√ (3/7)

Ans: θ = cos ^{- 1}√ (3/7)

iii. and

Ans:

|| =

We know that ,

⇒

⇒ ( - 1) = 2 cosθ

⇒ cosθ = - 1/2

⇒ θ = cos ^{- 1} - 1/2

⇒ θ = 120⁰

Ans: θ = 120⁰