Chapter 5.4, Problem 1E

In Problems 1 and 2, verify that the pair $x\left(t\right)$, $y\left(t\right)$ is a solution to the given system. Sketch the trajectory of the given solution in the phase plane.

$\frac{dx}{dt}=3y^3$, $\frac{dy}{dt}=y$;

$x\left(t\right)=e^{3t}$, $y\left(t\right)=e^t$