What is #int xsin3x #? Calculus Introduction to Integration Integrals of Trigonometric Functions 1 Answer Sihan Tawsik Jan 30, 2016 #-(x^2cos3x)/3-1/9sin3x+c# Explanation: #intxsin3xdx# #=x intsin3xdx-int[d/(dx)(x) intsin3 xdx]dx# #=-x^2(cos3x)/3-int[(cos3x)/3]dx# #=-(x^2cos3x)/3-1/3(sin3x)/3+c # #=-(x^2cos3x)/3-1/9sin3x+c# Answer link Related questions How do I evaluate the indefinite integral #intsin^3(x)*cos^2(x)dx# ? How do I evaluate the indefinite integral #intsin^6(x)*cos^3(x)dx# ? How do I evaluate the indefinite integral #intcos^5(x)dx# ? How do I evaluate the indefinite integral #intsin^2(2t)dt# ? How do I evaluate the indefinite integral #int(1+cos(x))^2dx# ? How do I evaluate the indefinite integral #intsec^2(x)*tan(x)dx# ? How do I evaluate the indefinite integral #intcot^5(x)*sin^4(x)dx# ? How do I evaluate the indefinite integral #inttan^2(x)dx# ? How do I evaluate the indefinite integral #int(tan^2(x)+tan^4(x))^2dx# ? How do I evaluate the indefinite integral #intx*sin(x)*tan(x)dx# ? See all questions in Integrals of Trigonometric Functions Impact of this question 2622 views around the world You can reuse this answer Creative Commons License