Once again, what am I doing? r of t times d of t, this is how much flows, what volume flows in over a very small interval d t, and then we're going to sum it up from t equals 0 to t equals 8. That's the power of the definite integral, and so this is going to be equal to the integral from 0 to 8 of 20 sine of t squared over 35 d t. And lucky for us, we can use calculators in this section of the AP exam, so let's bring out a graphing calculator where we can evaluate definite integrals. And so let's see, we want to do definite integrals so that I can click math right over here, move down. So this function f n integral, this is a integral of our function or a function integral right over here, so let me press enter. And the way that you do it is you first define the function, then you put a comma, then you say what variable is the variable that you're integrating with respect to, and then you put the bounds of integration. So I'm going to write 20 sine of, and just because it's easier for me to input x than t, I'm going to use x, but if you just use this as sine of x squared over 35 dx, you're going to get the same value.