Tìm: a) \[{\int {\left( {3x - \frac{1}{{{x^2}}}} \right)} ^2}dx\]; b) \[\int {\left( {7x\sqrt[3]{x} - \frac{1}{{\sqrt {{x^3}} }}} \right)} dx\] (x > 0). c) \[{\int {\left( {{3^{2x}} - 1} \right)} ^2}dx\]; d) \[\int {\left( {2 - 3{{\cos }^2}\frac{x}{2}} \right)} dx\].

Tìm:

a) \[{\int {\left( {3x - \frac{1}{{{x^2}}}} \right)} ^2}dx\];

b) \[\int {\left( {7x\sqrt[3]{x} - \frac{1}{{\sqrt {{x^3}} }}} \right)} dx\] (x > 0).

c) \[{\int {\left( {{3^{2x}} - 1} \right)} ^2}dx\];

d) \[\int {\left( {2 - 3{{\cos }^2}\frac{x}{2}} \right)} dx\].