Find the stationary points and linear approximating systems at each station of
1. dx/dt = x+x^2+y, dy/dt = y-xy
2. dx/dt = 4-2y, dy/dt = 12-3x^2
3. dx/dt = x(1-x-y), dy/dt = y(3/4 - y - (1/2)x)
(apply taylor series/partial derivatives, find eigenvalues and eigenvectors)