How to find the critical points of a 2x2 jacobian matrix in matlab?

I need to enter a 2x2 jacobian matrix into ML, and find the critical points of this matrix using the solve command

['2x' '1-2y' ; '-1-2y' , '-2x'].

Answer 1

[Roger Stafford]

Presumably the critical points are those for which the determinant of the matrix is zero, but you don't need matlab to solve that problem. You can work that out on the back of an envelope. There is only one such point.

For more complicated jacobians, you might need the 'contour' function in matlab to find a one-dimensional infinitude of them.

[Roger Stafford]

On looking at your question five days later, I see that my answer was in error. The critical points are actually all the points on the circumference of a circle of radius 1/2 with center at the origin (0,0). (You can still determine this on the back of an envelope.)