Which polynomial will definitely have nonreal zeros?
Hint: Use Descartes's rule of signs. A. x^3-2x^2-x-2 B.X^3-2x^2+x-2 C.x^3-2x^2 D.X^4-8x^2+16

Question

Which polynomial will definitely have nonreal zeros?
Hint: Use Descartes's rule of signs.  A. x^3-2x^2-x-2  B.X^3-2x^2+x-2 C.x^3-2x^2 D.X^4-8x^2+16

anonymous · Answer

@amoodarya

amoodarya · Answer

X^3-2x^2+x-2 =(x-2)(.....)

x^3-2x^2=x^2(x-2)

X^4-8x^2+16=(x^2-4)^2=(x-2)^2 *(x+2)^2

anonymous · Answer

what?

amoodarya · Answer

A,B has a one real root , and two unreal root(zero)
but c, d have  all real

amoodarya · Answer

one of them is correct ?
do you type question (A,B) correct?

anonymous · Answer

I can only pick one. This is too hard

amoodarya · Answer

attachment

amoodarya · Answer

I think question is not correct or you type it wrong !

amoodarya · Answer

BOTH OF A,B HAS ONE  real zero  , and 2 unreal zero
may be 
D is X^4+8x^2+16 instead of X^4-8x^2+16
so X^4+8x^2+16=(x^2+4)^2 
and has no real zero

anonymous · Answer

well it wasnt B, must be A