Originally Posted by
gva0324 Here I have a supposedly simple vector question but my answer seems to be wrong. What am I doing wrong?
A(1,3,2) u= i + 3j +k v= 3j-k
a) If vector AB = u - v what are coordinates of B
AB = OB - OA
OB = (u -v) + OA
OB = (2,3,4) ........... OK
b)i) Write down the parametric equation of the line L, passing thorugh the point A in the direction of AB.
L = OA + m(AB)
L = (1,3,2) + m(1,0,2) ........... <<<<<<<<<
ii) What is the value of m at which L cross the YZ plane.
L crosses the YZ plane when x= 0
(0,y,z) = (1,3,2) + m(1,0,2)
0 = 1 + m
y = 3
z= 2 + 2m
My problem here is that the z turns out to be zero. This is not possible since it says it crosses the YZ plane. What is wrong with this?