Question

How do you find the imaginary roots of y=-x^4+3x^3-2x+5
I know the real roots are irrational and about 2.9 and 1.2

Answer 1

if you knew them exactly you could factor and then solve the remaining quadratic equation. since you can only approximate them i would simply cheat
http://www.wolframalpha.com/input/?i=-x^4%2B3x^3-2x%2B5

Answer 2

I don't want to cheat I want to know how I can find them myself...-__-

Answer 3

i really can't imagine how you would do it. there is in fact a formula for solving a fourth degree polynomial but it is amazingly long and not that enlightening