Question

Linear Algebra
Use the determinants to find the values of x
| 1,3,x |
| 4,1,2 |
| 5,2,1 |

I don't get this question. Help?

Answer 1

this determinant = what ?

Answer 2

A is singular, doesn't give a determinants

Answer 3

If A is singular, then its determinant must be 0 :)

Answer 4

singular means det = 0..

Answer 5

yes..

Answer 6

so, how do I find x?

Answer 7

Get the determinant of your matrix. You'll end up with an expression with one unknown
( x )
Then equate it to 0. You'll basically have a linear equation in one variable, and then solve for x that way.

Answer 8

Thank you!

Answer 9

No problem :)