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## Homework Statement

there is a line through A : (1;-2; 1) and B : (0; 2; 3)

and the line through C : (4; 1;-2) and D : (2; 2; 2)

are they parallel?

## The Attempt at a Solution

i said no they weren't.

i had the lines as being:

(-t+1)i+(4t+2)j+(2t+1)k

and (-2t+4)i+(t+1)j+(4t-2)k

and then i took the cross product assuming constants don't count.

and got a determinant-y thing of 21 which is not 0 - why i said it wasn't parallel.

is my working correct?