$[$R$]$ Find

a$){\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{e^{2x}}{1+e^{2x}}dx$

b$){\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{e^{\frac{1}{x}}}{x^2}dx$

c$){\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}{3}^{x}dx$

d$){\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{e^{\sqrt[\phantom{2}]{x}}}{8\sqrt[\phantom{2}]{x}}dx$

e$){\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{lnx}{x}dx$

f$){\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}cotxdx.$