00:01
We are given three vectors, u, v, and j.
00:06
So u is the vector with standard form 2i minus 3j plus 4k.
00:21
V is the vector with standard form 3i plus j minus 2k, and w is the vector with standard form i plus 5j plus 3k.
00:51
In part a, we're asked to find u plus v.
01:00
We simply add like terms, so i get 2 plus 3 or 5.
01:05
I and i have negative 3 plus 1 or negative 2 j and 4 plus negative 2 or plus 2 k.
01:20
In part b we're asked to find 2u minus 3b plus 4 w.
01:35
Now in this case we'll first perform the scalar multiplication and then vector addition.
01:42
So we get 2 times u this is going to be 2 times 2 or 4i minus 6 j plus 8k plus and then negative 3 times v this is negative 9 i minus 3 j plus 6k and then for w so this is plus 4i plus 20 j plus 12k and now adding like terms i get 4 minus 9 9.
02:37
Plus 4 or a negative 1 i negative 6 plus negative 3 plus 20 or positive 11 j and 8 plus 6 plus 12 or 26 k so i get negative i plus 17 j plus 26 k there's actually a mistake so this should be negative i plus 11 j plus 26 k.
03:42
K.
03:44
The book was wrong...