U sink doc dv for is integrals term in differentiable resulting expression . simpler product than of other two terms where integrable , How x to and sin choose ? we let. If u = du = sin cos x x a fxsinxdx. = ( ii. complicated . are integrable and differentiable . dv= v doc doc x. 2 sin x ) - jil . cos xdx. If we let u - x du - I doc doc ex du = sin x doc t. V= k x cos x fees t sin x da x t. Spca ) always integrate doc cos a choose a e. " doc p cx ) and du = Spca ) sin x doc is e a polynomial. " doc ( or , sin accord or in as cos a. Iz doc dv = doc v - se. Cx ) g how to f f- cx ) doc.