As we now we can use StreamPlot to visualize first-order differential equations like:y'[x]==1+x-y
StreamPlot[{1, 1 + x - y}, {x, -3, 3}, {y, -3, 3}, Axes -> True,
Frame -> False]
But how about second-order differential equations? Such as y''[x]+2y'[x]+3y==0?Can we visualize it?

y'=x, then we can convert it into{y',x'}={{1,0},{-2,-3}}.{x,y}, then we can useStreamPlot– yode Jan 09 '24 at 06:38