Ma puteti ajuta , va rog , cu limitele astea ?

a) [tex]\lim_{n \to \00} \frac{sin2x+3sin4x}{sin5x+6sin7x}[/tex]
b) [tex]\lim_{n \to \00}sin\frac{1}{x} * ln (1+x)[/tex]
c) [tex]\lim_{n \to \infty} (2+sin x)* ln x[/tex]
d) [tex]\lim_{n \to \00} \frac{ln(1+x+x^{2} ) }{x+1}[/tex]
e) [tex]\lim_{n \to \00} \frac{3^{x+1}-3 }{3x}[/tex]