Obviously, the graph is x square +y square =1; Square of x-square of y =9? Intermediate closed part

Dz=(3x squared y+1)dx+(2x squared y+ 1)dy.

3. Is that a Z or a square or something? Can't see clearly

4. Is the matrix 1 or 1? - 1 0

? 1 ? -2 1 r

? 2 ? - 1 0 ? 2r？

If the first three terms are reduced to identity matrix matrix, we can find out whether R has roots.

R matrix? You can get X y z