Question

Find a+b, 2a+3b,|a|, and |a-b|. a=3i-5j+3k, b=2j-k

Answer 1

a+b=(2i−4j+3k)+(2j− k)=2i−2j+2k 2a+3b =2(2i−4j+3k)+3(2j− k)
= 4 i−8 j + 6 k + 6 j − 3 k = 4 i − 2j + 3k
|a| = 22 +(−4)2 +32 = √29
|a−b| =|(2i−4j+3k)−(2j− k)|=|2i−6j+4k|