As shown in the figure, the equation of curve C is y=f(x), and the point(3,2) is an inflection point of curve C. Lines 1 and L are tangent lines of curve C at points(0,)and(3,)respectively, and the intersection point is(2,4). Let the function f(x) have the third successive derivative and compute the definite integral: (x'+x)f"(x)dx.43→x01234