Question

vectors a=<3,2> b=<2,-1>, c=<7,1>
Find value of s and t, where c=sa+tb. How do I start this?

Answer 1

sa=<3s,2s>, and tb=<2t,-1t> ??

Answer 2

so you now have a system of equations:
3s + 2t = 7 and
2s - 1t = 1

Answer 3

ill try that.. but set 3s+2t=|c| guess its not right

Answer 4

ye its correct =)

Answer 5

thanks

Answer 6

no problem

Answer 7

but im still couldnt see how you can set them equal to something. like 3s+2t=7

Answer 8

is there rule or? cuz i use <i,j,k> so when adding, its all is, js, ks. like <3s+2t,2s-t>=|c|, but it turned out, cant be solved

Answer 9

they are the coefficients of the components

3<xs, ys> + 2 <xt + yt> = <xc, yc>

Answer 10

so 3 xs + 2 xt = xc and
3ys ++ 2yt = yt

** xs being the x component of s and ys being the y component etc

Answer 11

sorry that second one is meant to read 3ys + 2yt = yc

Answer 12

k, make sense. Thanks again