Question

given that a=3i-2j+k,b=2i-4j-3k and c=-i+2j+2k.find the magnitude of (i)a (ii)a+b+c (iii)a-3b-5c​

Answer 1

Answer:

(I) √14 (ii) √32 (iii) √326

Explanation:

a= 3i-2j+k

then (I) |a| = √3²+2²+1²= √14

now , given b=2i-4j-3k and c=-i + 2j+2k

by adding a+b+c

we get a+b+c = 4i-4j

therefore,(ii)|a+b+c|= √4²+4² = √32

now, a-3b-5c = 2i-18k

(iii)|a-3b-5c|= √2²+18² = √326

...hope u understand