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

Thanks

Printable View

- July 1st 2009, 12:00 AMStroodleMatrix Question
The point of intersection of the lines and is . Use a matrix method to find .

Thanks - July 1st 2009, 12:32 AMChris 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? - July 1st 2009, 12:47 AMStroodle
Awesome. Thanks for that. The text says the intersection point is and that the answer is , but I also get ...

- July 1st 2009, 04:31 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...