Answer
$x\to -\infty, y\to -\infty$ and $x\to \infty, y\to \infty$ for both functions.
See graphs below.
Work Step by Step
We have $P(x)=3x^3-x^2+5x+1, Q(x)=3x^3$
As $x\to -\infty, y\to -\infty$ and $x\to \infty, y\to \infty$ for both functions.
