Answer
$\displaystyle \lim_{t\rightarrow\infty}P(t)=-\infty$
The net income will at some point will become negative, and in time, continue to be more and more negative, without bound.
Work Step by Step
$t$ is "approaching $+\infty$" means that $t$ is assuming positive values of greater and greater magnitude.
See table below.
As $t$ assumes positive values of greater and greater magnitude, the function value is negative and grows in magnitude without bound.
So, we write
$\displaystyle \lim_{t\rightarrow\infty}P(t)=-\infty$
Thus, the net income will at some point will become negative, and in time, continue to be more and more negative, without bound.
