(adsbygoogle = window.adsbygoogle || []).push({}); 3D vector collsions- do u terat them differently??

hi upon attemptin the following questions, in which i just answered the Questions in the same manner as i would with a 2D vector, i keep getting them wrong and was hoping sum1 could tell me where my thinking is flawed:

Proove that L1 and L2 intersect, finding th position vecor of the point:

L1 = 13i+j+8k + T(2i-j+3k)

L2= -5i+2j-3k + B(2i+j-k)

i simply said for them to intersect let them have the same x y z coordinates at some time/point T (ie let T and B = T)

so that (13+2T)i+(1-T)j+(8+3T)k = (-5+2T)i + (2+T)j + (-3-T)k

such that set each coordinate equal to each other ie

13+2T = -5+2T

1-T = 2+T

8+3T = -3-T and if T value is equal for each point therfore intersect for that value of T.....however since i am on here this obviously doesnlt work,

the answ is 3i+6j-7k

another question involves finding the least distance between 2 particles, where again i applied same principles for 2D vecotrs in 3D vectors (ie minimise a length between the 2 bodies using calculus) however it dosnlt work either , so i am hoping somethin in this Q will unlock the key to my mistakes in the others.....thanks

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# Homework Help: 3D vector collsions- do u terat them differently?

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