So this is trapezoid number 5. Scroll down a little bit, get some more real estate. So it's going to be plus, I'll just write the plus over here, plus f of 5 plus f of 6 over 2 times our delta x. So let's see how we can simplify this a little bit. All of these terms, we have a 1 half delta x, so let's actually factor that out. So remember, this is our approximation of our area. So area is approximately, remember this is just a rough approximation, it's very clear actually.