the end behavior is that it goes positive and both ends (we look at x^4 ) and put in -inf and + inf and get +inf both times)
to get the y intercept let x=0 y intercept =144
to find the x intercepts we factor and find the zeros
using graphing technology we plot the function
we look at the ends of the graph if it goes down it goes to - inf, if it goes up it goes to + inf
the y intercept is where x=0
there x intercepts are where it crosses the x axis on the plot (there should be 4 unless some are imaginary)