Question 1051076
When x becomes very large, x^4 term drives the equation.  The other terms become insignificant.
When x is very large positive, x^4 is positive.  When x^4 is very large negative, (-x)^4 is also positive.  The function will be W shaped or U shaped, here U shaped.
{{{graph(300,200,-20,20,-10,100,3x^4-2x^2-7x+1)}}}