Assuming $f(x)=ax^3+bx^2+cx+d$
show that $\lim_{x\rightarrow\infty}f(x)$ and $\lim_{x\rightarrow -\infty}f(x)$ exists, find the limits.$a,b,c,d\in\mathbb{R}$
Well, I think the limits exists in extended real line and their values are simply $+\infty$ and $-\infty$. If I am missing something please help.