I.3.1.54 Indefinite Integrals

Condition: Find vague integrals: 1) \ (\ int \ frac {e^{2 x} -2 e^{x}} {e^{2 x} +1} d x \), 2) \ (\ int \ arcsin x d x \) 3) \ ( \ int \ left (x^{2} +1 \ right) 3^{x} d x \) \ (\ int \ frac {x^{3} -2 x^{2} -12 x-7} {x^{3} -3 x-2} d x \).