u= x^(1/3)3u^2 du = dx∫ cos[x^(1/3)] dx=∫ 3u^2.cosu du=∫ 3u^2 dsinu=3u^2.sinu -6∫ usinu du=3u^2.sinu +6∫ u dcosu=3u^2.sinu +6ucosu -6∫ cosu du=3x^(2/3).sin[x^(1/3)] +6x^(1/3).cos[x^(1/3)] -6cos[x^(1/3)] + C
