Integral Calculus
Adding up the rectangles…
Initializing Sorting Algorithms...
Sorting
Trees
Graphs
Preparing interactive visualizations...
Integral Calculus
Adding up the rectangles…
Draw the curve (u, v). The rectangle under its end point splits into two regions — ∫ u dv on one side, ∫ v du on the other — and that is the whole formula.
∫ x cos x dx: a product, and no substitution untangles it. Integration by parts picks u = x and dv = cos x dx, so du = dx and v = sin x. Now draw the curve traced by (u, v) = (x, sin x) as x runs from 0 to π/2.