Question

find magnitude of their resultant vector if A= 2i^ + 6j^ + 4k^ and B= i^- 2j^+8k^

Answer 1

Explanation:

costetha=A.B/|A|.|B|

=22/√56√69

=22/2√14√69

=11/√966

Answer 2

Answer:

The magnitude of resultant vector of given vectors is 13

Explanation:

Given that the vectors are

$A = 2i + 6j + 4k \\ B = i - 2j + 8k$

Resultant of two given vector is nothing but the sum of two vectors.Therefore,the resultant of two vectors is as follows

$R=A+B$

Substituting the known vectors,we get

$R=(2i + 6j + 4k) + (i - 2j + 8k) \\ = 3i + 4j + 12k$

The magnitude of the resultant vectors can be found as follows

$|R| = \sqrt{3 {}^{2} + 4 {}^{2} + 12 {}^{2} } = \sqrt{169} = 13$

Therefore,The magnitude of resultant vector of given vectors is 13

#SPJ3