Alright, let's do part b now. Find the second derivative of y with respect to x in terms of x and y. Determine the concavity of all solutions for the given differential equation in quadrant two. Give a reason for your answer. Alright, so first let's just find the second derivative. So we already know that dy, let me give myself a little bit more space actually. We already know that the derivative of y with respect to x is equal to two x minus y.