Question

Find all rational zeros of the polynomial function P(x)=x^4 + 2 x^3 - 13 x^2 + 4 x - 30.
Enter the rational zeros in a comma separated list. If there are none, enter "none".


-3| 1 2 -13 4 -30
-3 15 -6 30
1 -5 2 -10 0
so (x+3)(x^3-5x^2+2x-10
so
5| 1 -5 2 -10
5 0 10
1 0 2
so (x+3)(x-5)(x^2-0x+2)
then sqrt-8
so I got -3,5,i-sqrt2,i+sqrt2
where am I going wrong

Answer 1

In google type :

mathportal roots calculator

When you see list of result click on :

Online Polynomial Roots Calculator with explanation

When page be open in rectangle type :

x^4 + 2 x^3 - 13 x^2 + 4 x - 30

and cick option :

Find Roots


You will see solution step by step