Question

pls answer fast q 10
the answer given is c
pls tell me how

Answer 1

Howdy!!

your answer is ------

there are two possible values of third side of triangle .

Given, Vector A = i + 2j + 4k
& vector B = 5i
Let , third vector be C

when , all this 3 vectors are equiblerimun

then, C = B - A

=> C = 5i - i - 2j - 4k

=> C = 4i - 2j - 4k

now, magnitude of vector C is

√ 4^2 +(-2)^2 +(-4)^2

= √16+4+16

= √36

= 6


when, vector C is resultant of vector A and vector B .

then, C = A+B

=> C = i + 2j + 4k + 5i

=> C = 6i + 2j + 4k

now, magnitude of vector C is

√6^2 + 2^2 + 4^2

= √36+4+16

= √56


so, length of third side of triangle may be 6 or √56.

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hope it help you