Help with finding variables in vectors?
Relative to an origin O , the position vectors of points A , B and C are given by
vec(OA) = (0, 2, -3)
vec(OB) = (2, 5, -2)
vec(OC) = (3, p, q)
In the case where angle ABC is a straight line, find the values of p and q .
Relative to an origin
In the case where angle
1 Answer
Sep 21, 2017
Explanation:
"since A, B and C all lie in a straight line"
"then they are "color(blue)"colinear"
rArrvec(BC)=kvec(AB)larr" k is a scalar"
vec(AB)=ulb-ula=((2),(5),(-2))-((0),(2),(-3))=((2),(3),(1))
vec(BC)=ulc-ulb=((3),(p),(q))-((2),(5),(-2))=((1),(p-5),(q+2))
"to find k we can only use the direction values of the"
"x-components"
"that is "2to1rArrk=1/2
rArrp-5=3/2rArrp=13/2
rArrq+2=1/2rArrq=-3/2