00:01
Suppose u is a vector negative 5, 0, 2 and v is a vector 3, negative 4, 0.
00:08
We want to find the sum of u and v, u minus v, v minus u, a times u, negative one -third times v, and the linear combination 8u minus 3b.
00:22
So first let's calculate the sum of u and v, that is negative 5, 0, 2, plus 3, negative 4, 0.
00:37
And we know this operation is done component -wise and we get a new vector which is negative 5 plus 3, first component, second 0 plus negative 4 or 0 minus 4 and the third one is 2 plus 0.
00:56
And so we get negative 2, negative 4 and 2.
01:07
So u plus v is a vector negative 2, negative 4, 2.
01:20
Now let's calculate u minus v, that is negative 5, 0, 2, minus 3, negative 4, 0.
01:38
And that is negative 5 minus 3, 0 minus negative 4 is 0 plus 4 and 2 minus 0.
01:57
And that is equal to negative 8, 4 and 2.
02:11
And so we can say that u minus v is a vector negative 8, 4, 2.
02:20
Okay, now part 3, v minus u, that will be vector 3, negative 4, 0, minus vector negative 5, 0, 2.
02:47
And then that gives us 3 minus negative 5 is 3 plus 5, negative 4 minus 0 and 0 minus 2.
03:04
Finally this is equal to vector 8, negative 4 and negative 2.
03:22
So v minus u is the vector 8, negative 4, negative 2.
03:34
Which is the opposite or negative 1 times the vector u minus v found in part 2.
03:41
Good, so in part 4 we're going to calculate 8 times vector u, that is 8 times vector negative 5, 0, 2.
04:01
And the scalar times the vector is a new vector such that each component is the component, the corresponding component of the given vector times the scalar.
04:11
So we get 8 times negative 5, first component, then 8 times 0, second component and the third component 8 times 2.
04:26
That is we multiply the scalar by each of the components of the vector and that's a new vector...