Find all rational zeros of the polynomial

Question

find all rational zeros of the polynomial 

P(x)=x⁴-2x³-6x²-4x-16

its rational zeros are 

x1=

x2=

x3=

x4=

with x1≤x2≤x3≤x4

Answer 1

Dalia,

 

There are two and only two rational zeros of this polynomial: x = -2 and x = 4. To these we may also add

x= ±√2i but I don't interpret the question of having asked for imaginary roots.