Question

A = 3i-4j ,B= -i-4j
find:

Answer 1

\[A+B , |A+B|\]

Answer 2

So apparently from what you've drawn it's wanting vector addition of vectors a and b, and then the magnitude of the sum of vectors a and b?

Answer 3

Yes!

Answer 4

i'm still relatively new to vectors so i may be wrong but for the first one it's as simple as addingthe components of vects A/B. so add your coefficients of i and j,

Answer 5

2i-8j

Answer 6

i'd say thats correct =). of course someones probably going to want to check this just to make sure haha. okay and the second one youre going to want to find the magnitude of vect |A + B| so in order to find the magnitude you need to take the sqrt of the sum of each component squared.

Answer 7

What?
Do I square A and B and then add then?

Answer 8

mmmmm youre basically squaring the coefficients of i/j of both a/b and then summing all of that. then taking the square root of all of that. i'll help you get started. sec.

Answer 9

-i = 1 right?

Answer 10

mmmm -i's coefficient would be -1 since -1 * i = -i but the negatives dont matter anyway since it's being squared

Answer 11

so,
-1^2 +(-4)^2?

Answer 12

ok no actually i take that back sorry it's actually the magnitude of our new vector |A+B| that we found for part A! we aren't using the same vector components. so ignore what i drew actually. again sorry! we're going to use that 2i -8j vector we found =)

Answer 13

so we're squaring 2 and -8, summing them, and then taking the square root of all of that.

Answer 14

60?

Answer 15

er 64 + 4 right? cause 8^2 = 64 and 2^2 = 4

Answer 16

that'd be 68 =]

Answer 17

and then square root of that.

Answer 18

8.2?

Answer 19

yes! if they want you to round to a certain decimal amount then be careful but otherwise yes 8.2 :P

Answer 20

THANKS!

Answer 21

were these multiple choice or?

Answer 22

and np but still i'd be careful i'm really new to vectors still ;p

Answer 23

@agent0smith am i right? :3

Answer 24

A = 3i-4j ,B= -i-4j

\[\large A+B = 2i - 8j\] \[\Large |A + B| = \sqrt{2^2+8^2}\]

Answer 25

thats what i had yayyyy

Answer 26

MY DANNO ;u;

Answer 27

I just didn't feel like reading it

Answer 28

;l all good.