Find-the-resolved-part-of-the-vector-a-6i-3j-9k-in-the-diection-of-b-2i-2j-k-please-help-i-got-the-answer-to-be-1-

Question Number 5620 by sanusihammed last updated on 22/May/16

F i n d t h e r e s o l v e d p a r t o f t h e v e c t o r a = 6 i - 3 j + 9 k

i n t h e d i e c t i o n o f b = 2 i + 2 j - k

p l e a s e h e l p .

i g o t t h e a n s w e r t o b e (- 1)

Commented by prakash jain last updated on 22/May/16

1 . Find angle between two vectors using

the relation

a \cdot b =∣ a ∣∣ b ∣ \cos θ \Rightarrow \cos θ = \frac{a \cdot b}{∣ a ∣∣ b ∣}

2 . Magnitude of resolution of a in direction

of b =∣ a ∣ \cos θ

3 . Direction of resolution is same as b

so find unit vector in direction of b = \frac{b}{∣ b ∣}

4 . Resolution of a in the direction of b

= (magnitude of resolution from 3) \times

(unit vector in the direction of b from 4)

Commented by prakash jain last updated on 22/May/16

Your answer is a scalar while you will need

to get a vector .