Leo read a line. Then another. For the first time in four hours, something clicked. The professor had said “use u-substitution,” but Paul showed him. Paul gave him a color-coded example. Paul even highlighted the “Common Mistakes” in a little red box.
He typed: tutorial.math.lamar.edu
He smiled. He could hear Paul’s voice in his head: “Alright, let’s work an example. This is a classic integration by parts problem. You’re going to let u = x^3 and dv = sin(x) dx. It’s going to take three passes, but you’ve got this.”