Indefinite Integration

a$).{\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}{x}^{2}sin(x^2)dx$

b$).{\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{x}{x^4-4}dx$

c$).{\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{arctan(x^2)}{x^3}dx$

d$).{\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{1}{\sqrt[3]{8-x^2}}dx$