So there are a few tricks and rules for simple function visualisation, however this becomes more complex the higher grade of function you get (x^3,x^4 etc.)

The easiest way to see what happens when changing functions like this is to plot both of them for a few values of x. Say for example you choose a range of -5<x<5 and plot both functions. This will give you the best understanding of what happens and changes when adapting your functions!