integrate (x*sin (3*x),x)

integrate(x*sin(3*x), x)

plot(-x*cos(3*x)/3 + sin(3*x)/9)

solve(-x*cos(3*x)/3 + sin(3*x)/9, x)

diff(-x*cos(3*x)/3 + sin(3*x)/9, x)

series(-x*cos(3*x)/3 + sin(3*x)/9, x, 0, 10)

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