So what we get is one over natural log of a times one over x, which we could write as one over natural log of a times x, times x, which is a really useful thing to know. So now we could take all sorts of derivatives. So if I were to tell you f of x is equal to log base seven of x, well, now we could say, well, f prime of x is going to be one over the natural log of seven times x. If we had a constant out front, if we had, for example, g of x, g of x is equal to negative three times log base, I don't know, log base pi. Pi is a number. Log base pi of x, well, g prime of x would be equal to one over the, oh, let me be careful. I have this constant out here, so it'd be negative three over, it's just that negative three, over the natural log of pi, so it's just the natural log of this number, times x.