Y RAJYALAKSHMI11 Years agolet u = x ; v = cosnxdu = dx; ∫v = sinnx/nThis is in the form of ∫uv = u∫v – ∫∫v.du∫xcosnxdx = xsinnx.n – ∫sinnx/n dx= xsinnx/n – ( – cosnx/n)/n = xsinnx /n + cosnx / n2