But we've just evaluated this definite integral. Now another way to do it is to think about the, is to try to solve the indefinite integral in terms of x and use u substitution as an intermediate. So one way to think about this is to say, well let's just try to evaluate what the indefinite integral of two x times x squared plus one to the third power dx is. And then whatever this expression ends up being algebraically I'm going to evaluate it at x equals two and at x equals one. And so then you use the u substitution right over here and you would get, this would simplify using the same substitution as the integral of u, u to the third power du, u to the third power du. And once again you're going to evaluate this whole thing from x equals two and then subtract from that, it evaluated at x equals one. And so this is going to be equal to, well let's see, this is u to the fourth power over four.