3-D Vectors

• Dec 11th 2009, 05:58 AM
Oasis1993
3-D Vectors
Hello.

a) Find a vector equation for the line L through (3,2,6) parallel to the line with vector equation r = (4,0,5) + t(-3,1,2)

b) Find also the coordinates of the points where L meets the xy-plane and the xz-plane.

• Dec 11th 2009, 07:06 AM
HallsofIvy
Quote:

Originally Posted by Oasis1993
Hello.

a) Find a vector equation for the line L through (3,2,6) parallel to the line with vector equation r = (4,0,5) + t(-3,1,2)

I'm wondering why you ask. If know anything at all about "vector equations of lines" (which you certainly should to be trying to solve this) the answer should be obvious- no calculation required at all!

Let me point out that the equation you give is of a line through (4, 0, 5) (just take t= 0). What does the (-3,1,2) represent?

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b) Find also the coordinates of the points where L meets the xy-plane and the xz-plane.
Well, you know that in the xy-plane, z= 0. What is the value of the parameter when z= 0? In the xz-plane, y= 0. What is the value of the parameter when y= 0?

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