Question

please help.. idk how to even figure this out so steps would be nice too.
Find the specified vector or scalar.

u = -4i + 1j and v = 4i + 1j; Find . ||u+v||

A. Sqrt34

B. 8
C. 5
D. 2

Answer 1

first add the "corresponding" terms
then find the length of the resulting vector
(length is sqrt(sum of square of each term))

Answer 2

for example the length of 3i+4j is
\[ \sqrt{3^2+4^2} = \sqrt{9+16}= \sqrt{25} = 5\]

Answer 3

hey thank you for that a answer can you show me how you got got the length of the vector

Answer 4

what did you get for u+v?

Answer 5

wait i misunderstood i thought that was the same thing. im so confused

Answer 6

first add corresponding terms gives us... i+2j ?

Answer 7

idk how to find the length of a vector

Answer 8

-4i + 1j
4i + 1j

Answer 9

-4i + 4i is not i

Answer 10

its 0?

Answer 11

i dont understand the whole vector and scalar thing

Answer 12

yes, the i's "go away"
you are left with 2j

Answer 13

which is positive points?

Answer 14

in 2-dimensions, you can think of the vector as <x,y> pair of numbers
for example, u= -4i + 1j (which can also be written <-4,1>
in a graph, it looks like this:

Answer 15

and the length of the vector is the length of the line from (0,0) (the origin) to the point (-4,1)
we use pythagoras to find its length

Answer 16

okay so U is a vector and length would be to the point.

Answer 17

oh okay i didnt see your message

Answer 18

u+v = 2j (or 0i+2j, or (0,2) )
in a graph it looks like this