# Equation of lines

• Mar 19th 2013, 05:40 AM
99.95
Equation of lines
How would I find the

parametric equations for the line through (2,4,6) that

is perpendicular to the plane x-y+3z=7

It is my understanding that to find the equation of a line i need a parallel vector and a point.

Im assuming I have to do something with the normal vector (1,-1,3) but it's not parallel to the line in question, so what could i possibly do?

thanks.

and also,

find the equation of a line passing through (2,1,0) and perpendicular to both i + j and j + k

• Mar 19th 2013, 06:28 AM
HallsofIvy
Re: Equation of lines
Quote:

Originally Posted by 99.95
How would I find the

parametric equations for the line through (2,4,6) that

is perpendicular to the plane x-y+3z=7

It is my understanding that to find the equation of a line i need a parallel vector and a point.

Im assuming I have to do something with the normal vector (1,-1,3) but it's not parallel to the line in question,

Why would you say that? The line is to be perpendicular to the plane and the normal vector (1, -1, 3) is perpendicular to the plane. How many perpendiculars to you think a plane has?

Quote:

so what could i possibly do?

thanks.

and also,

find the equation of a line passing through (2,1,0) and perpendicular to both i + j and j + k
Quote: