And so we should be able to figure out h prime of x. Or we could just rewrite it this way. We could rewrite that h prime of x is equal to, is equal to one over g prime of h of x. Now in some circles, they might encourage you to memorize this, and maybe for the sake of doing this exercise on Khan Academy, you might want to memorize it. But I'll tell you, 20 years after I took calculus, or almost 25 years after I took calculus, this is not something that I retain in my long term memory, but I did retain that you can derive this from just what the definition of inverse functions actually are. But we can use this now if we want to figure out what h prime of three is. H prime of three is going to be equal to one over, one over, one over g prime of h of three, which I'm guessing that they have given us.