How do you evaluate this sequence limit using the squeeze/sandwich theorem? $$\lim_{n \to \infty} \left(3^n+1\right)^{\frac1n} $$
I don't really know where to start. I've tried using the fact that $\lim_{n \to \infty} \left(3^n\right)^{\frac1n} = 3$ (which is the correct answer) but I don't know where to go from there.
Thanks!