Question

Could anyone give me a refresher? How do you find the line of intersection in a 3x3 system of equations?

Answer 1

same as a ...what a miute, thats a matrix aint it

Answer 2

elimination is still the same process....

Answer 3

if you know 3 points, you can solve for a 3x3

Answer 4

No, because it's a LINE of intersection, not a point.

Answer 5

right, the three planes interesect at a line instead of a point.

Answer 6

if you look at it head on its 3 lines at a single point if I recall correctly. kinda like a churro :)

Answer 7

Lol... or an asterisk? But, I still need the line itself, not just a point.

Answer 8

we got any examples to muddle thru?

Answer 9

if you have a system of three equations (in three variables i'm guessing), they can intersect at a point or a line.

Answer 10

solving quadratics by just the points is finding a solution to 3 planes that come to a point... :)

Answer 11

if they intersect in a line, you get infinite solutions, so you should be able to just parameterize the solution from rref your matrix.

Answer 12

Isn't there a way to do it without reduced row echelon form?

Answer 13

rref is the most simple way that i know.

Answer 14

you may not have to reduce it all the way.

Answer 15

if you can notice by inspection that one eq. is a linear combo. of the other.