Geometery
Author 
Message 
Cozzy

Posted: Thu May 13, 2004 8:36 am Post subject: Geometery 


Hey anyone know how to do this problem
Random point = A(2,1,1)
Plane = 6x7y+2z=0
a) determine a point, x, on the plane
b) determine the magnitude of the projection of A(vector X) on the normal vector to the plane.
c) explain the signifince of the magnitude
plz show answer if u can
please
thx 





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Dan

Posted: Thu May 13, 2004 1:55 pm Post subject: (No subject) 


AHHHHHHHHHHHHHHHHHHHHHHHHHH not geo math, it burns my eyes!!!!!!!
Why are you trouching us with such evil........ 
Computer Science Canada
Help with programming in C, C++, Java, PHP, Ruby, Turing, VB and more! 




Cozzy

Posted: Thu May 13, 2004 5:37 pm Post subject: come on help me 


come on dan, if u dont help me ill get tony to ban u from this site
lol or else ill just go over 2 his house and play midnight club more
BUT SOMEONE HELP ME PLEASE 





Dauntless

Posted: Thu May 13, 2004 8:13 pm Post subject: (No subject) 


Dan can't get banned...he's the CRAZY ADMIN....... Crazy, you hear me? 





Delos

Posted: Thu May 13, 2004 8:49 pm Post subject: Re: Geometery 


Cozzy wrote: Hey anyone know how to do this problem
Random point = A(2,1,1)
Plane = 6x7y+2z=0
a) determine a point, x, on the plane
b) determine the magnitude of the projection of A(vector X) on the normal vector to the plane.
c) explain the signifince of the magnitude
plz show answer if u can
please
thx
a)
Determine a couple of points on the plane.
eg. the x/y/z intercepts (by setting others to 0).
Then, figure out 2 direction vectors.
Convert the eqn into Vector form.
Bu now you already have a bunch of points.
But the vector eqn is a beut for the rest of the problems.
b)
Just do the usual projection thing w/ dot products.
c)
Magnitude...what do you think it is ! 





octopi

Posted: Thu May 13, 2004 9:01 pm Post subject: Re: Geometery 


Cozzy wrote: Hey anyone know how to do this problem
Random point = A(2,1,1)
Plane = 6x7y+2z=0
a) determine a point, x, on the plane
b) determine the magnitude of the projection of A(vector X) on the normal vector to the plane.
c) explain the signifince of the magnitude
plz show answer if u can
please
thx
Okay, well....Part A you just need to find a few numbers that satisfy the equations.
6x7y+2z = 0
So, you just pick random values to x, and y, and then calculate z
6(1)7(2)+2(4) = 0
ptX=(1,2,4)
the normal to the plane is (6, 7, 2) isn't it?
Is part b asking us to make a vector XA? using two points?
ptX(1,2,4)  ptA(2,1,1)
vctXA(3,3,3)
now project vctXA onto the normal:
=dot(vctXA,NORMAL)/MAG(NORMAL)
=3/sqrt(89)
or, I messed up, and its
3/sqrt(27)
I dunno, I suck at this class. 





Dan

Posted: Thu May 13, 2004 9:01 pm Post subject: Re: come on help me 


Cozzy wrote: come on dan, if u dont help me ill get tony to ban u from this site
lol or else ill just go over 2 his house and play midnight club more
BUT SOMEONE HELP ME PLEASE
turst me you dont whont me helping you with geo math, that class is the worst i have ever done in a subject in high school. 
Computer Science Canada
Help with programming in C, C++, Java, PHP, Ruby, Turing, VB and more! 





