Question

r(t)=(1-t)<-2,-1>+t<1,2>
the answer is < -2+3t,-1+3t> but i can't understand how can we do this calculation

Answer 1

multiply ?

Answer 2

(-2(1-t), -1(1-t)) +(t, 2t)

Answer 3

no

Answer 4

ordered pairs.. what i guessed

Answer 5

=(-2+2t+t,-1+t+2t)
=(-2+3t, -1+3t)

Answer 6

i cant make out what the quaestion is asking for lol

Answer 7

maybe its the addition of 2 vectors from initial points? or the distance between then or something....

Answer 8

scalars and addition....ok got it

Answer 9

it is in line integral notes

Answer 10

it is vector notation.

the () are equations to calculate the scalar functions of each vector; hence(1-t) and (t) cahnge the size of the arrow that represents each vector..

Answer 11

6<2,3> is an arrow from the origin to a point (2,3); the scalar says to multiply those values by 6 in this case...

<6(2),6(3)> = <12,18>which is an arrow from the origin to a point (12,18)

Answer 12

(1-t)<-2,-1> means to scale the vector by whats in the ():

<-2(1-t),-1(1-t)> = <-2+t,-1+t>

Answer 13

vector t<1,2> is scaled to :

<1t,2t>.... now add the vectors together

Answer 14

<-2+t, -1+t>
< 1t , 2t >
-------------
<-2t+2t, -1+3t>

Answer 15

gotta read thru the typos lol

Answer 16

now u really need some vitamin :P

Answer 17

-2(1-t) why that's answer isn't -2+2t :S you write -2+t

Answer 18

oh yes... i mistake, u r right

Answer 19

you gotta read it for what it is; not for the typos in it lol

Answer 20

if i type 2+6=9....you gotta have sense enough to understand that im an idiot and look past the fat fingers to the message itself lol

Answer 21

how sweet ..... suppose u r a teacher, n marking the scripts, underlining the mistakes, n get the same reply from the student ;)

Answer 22

just kidding :P

Answer 23

here most of the things must be understood :)

Answer 24

lol

Answer 25

i think my question can't replied but thanks

Answer 26

oh no... u may ask where r u confused

Answer 27

just go on :)

Answer 28

If you know about vectors and scalars of vectors and addition of vectors; then the question is answered...

Answer 29

n<x,y> + m<p,q>

<nx ,ny>
+<mp,mq>
----------
<nx+mp, ny+mq>

Answer 30

thanks:D