-3
$\begingroup$

Determine the conditions on a,b,c, and d for the following matrix to have reduced echelon form $\begin{pmatrix} a&b\\ c&d \end{pmatrix} \sim \begin{pmatrix} 1&0\\ 0&1 \end{pmatrix}$

  • 1
    It will be rref-equivalent to the identity if and only if it is invertible. that implies...2017-01-13
  • 0
    If you want your questions to be readable, it is much better if you write the equations using MathJax (you can find more info about it at http://meta.math.stackexchange.com/questions/5020/mathjax-basic-tutorial-and-quick-reference). Also, when you ask a question here it's better to explain what you have tried, and what's giving you trouble.2017-01-13

1 Answers 1

1

One way to do this is with determinants. $A$ reduces to the identity matrix $\iff$ $det(A)\neq 0\iff ad-bc\neq 0...$