Plot y = 



I used this online solver specially designed to find polynomial roots (zeroes)

https://www.mathportal.org/calculators/polynomials-solvers/polynomial-roots-calculator.php


                 BELOW IS WHAT THE SOLVER produced:


The roots of the polynomial 2x4−5x3+10x2−9 are:

x1=1.14223
x2=−0.77304
x3=1.06541+1.99028∗i
x4=1.06541−1.99028∗i


Explanation

This polynomial has no rational roots that can be found using Rational Root Test.

Roots were found using quartic formulas (opens new window)