And so this is going to be equal to, well let's see, this is u to the fourth power over four. And once again evaluating it at x equals two and then subtracting from that at x equals one. And then now we can just back substitute. We could say hey look, u is equal to x squared plus one. So this is the same thing as x squared plus one to the fourth power over four. And we're now going to evaluate that at x equals two and at x equals one. And you will notice that you will get the exact same thing.