1. The problem statement, all variables and given/known data Evaluate the following determinant by expressing the matrix in upper triangular form. 2. Relevant equations row operations. 3. The attempt at a solution http://yfrog.com/jnscan0001ugj http://img707.imageshack.us/img707/6379/scan0001ug.jpg I want to know what I did wrong there cause I cant figure it out the calculator shows a different answer.
In your 4th (or so) step, you replaced row 2 by 1/2 itself. Replacing a row by a nonzero multiple of itself is one row operation that changes the value of the determinant. The other row operation that does this is swapping two rows. The correct value of the determinant is -17.