SOLUTION: Hello, I was wondering if I could have some help solving this question, thanks:
The link to the diagram of the question is here: http://puu.sh/2nCh3
The shape in this question
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-> SOLUTION: Hello, I was wondering if I could have some help solving this question, thanks:
The link to the diagram of the question is here: http://puu.sh/2nCh3
The shape in this question
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Question 730194: Hello, I was wondering if I could have some help solving this question, thanks:
The link to the diagram of the question is here: http://puu.sh/2nCh3
The shape in this question is a parallelepiped.
1. Find the area of the parallelogram OAFE.
for this i found the cross product to be:
{4i + 3j - 15k}
and so the area to be : {15.8u^2}
however im not sure whether the vectors should of been {OA=3i} and {0E=0i+5J+1k} instead of {AO=-3i}.
I also tried to see whether the vectors are perpendicular but found that the cross product of AO is -12 while for OE is 0. Shouldn't they both be zero to be perpindicular and if so have i done this wrong or are they not perpendicular.
2.Find the area of triangle OAF.
for this i know to use the rule {{1/2}*|a*b|} which would give the area OAF is {7.9u^2} but im not sure.
3. Find a unit vector that is perpendicular to the face OABC.
4. Find the volume of the parallelepiped.
i know the rule is {|a|*|b|*|c|*sinx*cosx} and then you find the cross product and so the answer from question 1 is used {4i + 3j - 15k} .
Is the dot product used for that resultant vector with the OC??
Thank you for having a look at the question and any help would be greatly appreciated! Answer by lynnlo(4176) (Show Source):
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