And I encourage you to pause the video and try to figure it out on your own. All right, so in order to evaluate this, we need to remember the fundamental theorem of calculus, which connects the notion of a definite integral and an antiderivative. So the fundamental theorem of calculus tells us that our definite integral from a to b of f of x dx is going to be equal to the antiderivative of our function f, which we denote with a capital F, evaluated at the upper bound minus our antiderivative evaluated at the lower bound. So we just have to do that right over here. So this is going to be equal to, well, what is the antiderivative of four? Well, you might immediately say, well, that's just going to be four x. You could even think of it in terms of reverse power rule.