Concept:Some useful formulas are:\(\rm \int {1\over x} dx =ln\ x + C\) ? sinax dx = \(\rm -cosax\over a\) + C\(\rm ? x^n dx = \frac {(x^{n+1})} {(n+1)} +C; \ n?1\)Calculation:\(\rm \int ({{2x-3x^3}\over x^2} + sin3x) dx\)= \(\rm \int {2\over x}dx-\int3x\ dx + \int sin3x \ dx\)= \(\rm 2\ lnx - {3\over2}x^2 - {cos3x\over 3} + C\), where C is the constant of integration