The point of intersection of the lines and is . Use a matrix method to find .

Thanks

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- Jun 30th 2009, 11:00 PMStroodleMatrix Question
The point of intersection of the lines and is . Use a matrix method to find .

Thanks - Jun 30th 2009, 11:32 PMChris L T521
You need to apply row reduction methods to this matrix:

Since the intersection point is (2,1), its matrix representation would be , it follows that and

However, if I solve the first equation for a, I get , but when I solve the second equation for a, I get ....(Wondering)

Did you copy the intersection pt correctly? - Jun 30th 2009, 11:47 PMStroodle
Awesome. Thanks for that. The text says the intersection point is and that the answer is , but I also get ...

- Jul 1st 2009, 03:31 AMpfarnall
The problem is that the second line doesn't even pass through the point of intersection!

Basically I think the second equation should be and then as far as I can see a=7 is the answer, which makes sense given that if you plug (2,1) into the first line equation you get ... 7. No real need for matrices here I fear...