Question

Given that P=(-7,16) and Q=(-8,7), find the component form and magnitude of QP PLEASE HELP MEDAL AND FOLLOW WILL BE GIVEN!!!
@sleepyhead314

Answer 1

"find the component form"

you subtract the corresponding coordinates in the same order (tail - head)

y2 - y1 = 7 - 16 = -9
x2 - x1 = -8 - (-7) = -8 + 7 = -1

so PQ in component form is <-1, -9>

this tells us that to go from (-7,16) to (-8,7) we need to go 1 unit to the left and 9 units down

Answer 2

what do you mean?

Answer 3

all I do is subtract the ys and the xs? why didn't some one tell me that earlier! is the answer <-1,-9>, square root 82?

Answer 4

yep you just subtract the ys to get the change in y
subtract the xs to get the change in x

the order is (tail - head) which means you start with the ending point and subtract off the starting point

Answer 5

\[\Large \sqrt{82}\] is the correct answer to the second part

Answer 6

this is the distance from P to Q, in other words, the length of the vector

Answer 7

thank you can you help me with a couple more?

Answer 8

sure

Answer 9

Evaluate the expression
r=<7,-3,-7>
V=<4,6,-5>
w=<-5,-6,-3>
v-w

Answer 10

@jim_thompson5910

Answer 11

v - w is the same idea as finding the component form

you subtract the coordinates (start with v, subtract off w)

Answer 12

example: the x coordinate of v is x = 4, the x coordinate of w = -5

subtract the x coords: Vx - Wx = 4 - (-5) = 4 + 5 = 9

Answer 13

I did but I didn't get anything close to my options

Answer 14

@jim_thompson5910

Answer 15

what did you get?

Answer 16

20

Answer 17

and my options are
-41
<-20,-36,15>
<-28,18,-35>
-9

Answer 18

@jim_thompson5910

Answer 19

are you sure it's v - w?

and it's not like 2v - 3w ?

Answer 20

yes it just says v-w

Answer 21

well that's just odd

Answer 22

one of the options should have 9 in the x coordinate

Answer 23

which one is the closest?

Answer 24

none of them sadly, idk what to do here. Can you post a screenshot of the full thing?

Answer 25

no but ill retype it
evaluate the expression
r=<7,-3,-7>
v=<4,6,-5>
w=<-5,-6,-3>
v-w

Answer 26

that's all it gives me

Answer 27

it's also odd how they mention vector r but don't use it in v-w

Answer 28

it seems like there is a typo, but idk

Answer 29

me ether -.- thanks though

Answer 30

sadly there's not much I can do other than tell you to ask your teacher about it. S/he would know if there's a typo or not. If so, then you'd get free points