So this is going to be the same thing as 1 over 25 times the derivative of W. And the derivative of W is this. The differential equation literally tells us the derivative of W is this over here. So 1 over 25 times 1 over 25 WT, or the function W as a function of T, minus 300. And so we can say the second derivative of W as a function of T is equal to 1 over 625 times W as a function of T, which is a function of T, minus 300. So we've done the first part. We've found out the second derivative of W in terms of just W. Now let's try to address the second part of their question. So we did the first part.