- #1
Jbreezy
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Homework Statement
A corner,A , of a parallelepiped ABCDEFGH, has position vector <3,7,4> and the points B,G,D that are neighboring vertices A of have position vectors< 2,9,7>, < 5,10,10> ,< 4,11,9 > , respectively. Find the volume of the parallelepiped in cubic units
Homework Equations
Triple scalar product in general a cross b dot c
The Attempt at a Solution
OK, so I know what to do but I don't know if I did the right things. First I tried to draw it this was kind of hard because I'm not so good at orientating my axes so I can see what I'm looking at.
I want..I think
(g-d) cross ( a -b) dot (b-d)
OK I did
(g-d) = < 5,10,10> -< 4,11,9 > = < 1 ,-1, 1>
(a - b) = <3,7,4> -< 2,9,7> = < 1,-2,-3>
(g-d) cross (a - b) = < 5, 4, -1>
Then, dot this with vector ( b - d) = < 2,9,7> - <4,11,9> = <-2,-2,-2>
< 5, 4, -1> dot <-2,-2,-2> = 39 cubic units?
I feel like if I did this wrong it is because of my drawing maybe. Thanks.