So one solution to this differential equation, and I'll just write it as our first one, so one solution, I'll call it y one, and I could even write it as y one of x to make it explicit that it is a function of x. One solution is y one of x is equal to e to the negative 3x. And I encourage you to pause this video right now and find the first derivative of y one or the second derivative of y one and verify that it does indeed satisfy this differential equation. So I'm assuming you've had a go at it, so let's work through this together. So that's y one. So the first derivative of y one, well, this is going to be, let's see, we just have to do the chain rule here, derivative of negative 3x with respect to x is just negative three, and the derivative of e to the negative 3x with respect to negative 3x is just e to the negative 3x. And if we take the second derivative of y one, this is equal to, same exact idea, derivative of this is negative three times negative three, it's going to be nine e to the negative 3x.