I have an integral from 0 to 1, of sin(x2). I need to, with n=5 rectangles midpoint approximate it. I've figured that I need something like i=1 and ending at 5 (right?), and the equation is just sin(x2) Δx Delta x is 1/5. Are those the correct steps? I think that all I need to do.... is... uhh.......... Well, actually I'm not sure how to change x2. Should it be xi2? If that's true, then I think all I need to do, to midpoint approxy is keep on incrementing i, and I think it naturally gives me a midpoint, right?