What is the projection of (32i-38j-12k) onto (18i -30j -12k)?

1 Answer
ali ergin
Feb 14, 2016

vec c= <24,47i,-40,79j,-16,32k>

Explanation:

vec a= <32i,-38j,-12k>
vec b= <18i,-30j,-12k>
vec a * vec b =18*32+38*30+12*12=
vec a * vec b=576+1140+144=1860
|b|=sqrt(18^2+30^2+12^2)
|b|=sqrt(324+900+144)
|b|=sqrt1368
vec c=(vec a*vec b)/(|b|*|b|)*vec b
vec c=1860/(sqrt 1368 *sqrt 1368)<18i,-30j,-12k>
vec c=1860/1368<18i,-30j,-12k>
vec c= <(1860*18i) /1368, (-1860*30j)/1368,(-1860*12k)/1368>
vec c= <24,47i,-40,79j,-16,32k>

Related questions
See all questions in Vector Operations
Impact of this question
1339 views around the world
You can reuse this answer
Creative Commons License