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KatClaire
Group Title
Find the equation of the line of intersection of the planes with the equations 3x+4y+z=1 and 5x3z=5
 one year ago
 one year ago
KatClaire Group Title
Find the equation of the line of intersection of the planes with the equations 3x+4y+z=1 and 5x3z=5
 one year ago
 one year ago

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KatClaire Group TitleBest ResponseYou've already chosen the best response.0
Please help me work it out step by step :(
 one year ago

cherio12 Group TitleBest ResponseYou've already chosen the best response.2
alright so you will have to use the cross product of the two normal vectors
 one year ago

KatClaire Group TitleBest ResponseYou've already chosen the best response.0
I did and I got 12i4j20k
 one year ago

cherio12 Group TitleBest ResponseYou've already chosen the best response.2
hm...how'd u get yours?
 one year ago

cherio12 Group TitleBest ResponseYou've already chosen the best response.2
wait...i got it
 one year ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.0
practice makes perfect, good job so far cherio ;)
 one year ago

cherio12 Group TitleBest ResponseYou've already chosen the best response.2
haha..gotta love calc =D..and ya i got 12i4j20k after i set it up right
 one year ago

cherio12 Group TitleBest ResponseYou've already chosen the best response.2
so this is your direction vector i believe
 one year ago

cherio12 Group TitleBest ResponseYou've already chosen the best response.2
now you need to to find a point that lie on this line
 one year ago

cherio12 Group TitleBest ResponseYou've already chosen the best response.2
you can do this by taking your two planes and setting x,y, or z to zero and finding a point
 one year ago

KatClaire Group TitleBest ResponseYou've already chosen the best response.0
okay so if x=0 I get y=2/3 and z=5/3 , right?
 one year ago

cherio12 Group TitleBest ResponseYou've already chosen the best response.2
yes, so for the next part you have to make a vector with that point (this will be dotted with the direction vector from before)
 one year ago

cherio12 Group TitleBest ResponseYou've already chosen the best response.2
so typically for a line you just select the (x,y,z) to be your point (if anything doesn't make sense let me know) so you get (x0, y(2/3), z+(5/3)) as that vector
 one year ago

cherio12 Group TitleBest ResponseYou've already chosen the best response.2
now i dot it with any scalar of the direction vector and get L=(x, y(2/3), z+(5/3))* t(12,4,20)
 one year ago

KatClaire Group TitleBest ResponseYou've already chosen the best response.0
Any reason why you do (x0,y(2/3),z+(5/3)? and you can't simplify that any more so that would be the answer?
 one year ago

cherio12 Group TitleBest ResponseYou've already chosen the best response.2
well if you want to write in parametric or (something that starts with a s...symmetric?) you can simplify it a bit more..but as far at why x,y,z...um..i'll try to draw a picture.
 one year ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.0
in case i missed it, since the second plane has no y value, wouldnt it be simper to make y=0 in the first to solve for x,z ?
 one year ago

cherio12 Group TitleBest ResponseYou've already chosen the best response.2
dw:1359565267353:dw
 one year ago

cherio12 Group TitleBest ResponseYou've already chosen the best response.2
i just set x=0, so i didn't have to do substitution. other way works too
 one year ago

cherio12 Group TitleBest ResponseYou've already chosen the best response.2
okay..not to try to explain the picture...
 one year ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.0
i get a common point of (2,0,5) :) but any common point will suffice
 one year ago

KatClaire Group TitleBest ResponseYou've already chosen the best response.0
well either way, I think I understand it more now! I was confused as to why the cross product was involved and what not. Thanks!!
 one year ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.0
crossing vectors created a new vector perp to both crossing 2 plane normals will get you a direction vector that is parallel to the line of insection
 one year ago

KatClaire Group TitleBest ResponseYou've already chosen the best response.0
Yes! thank you
 one year ago
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