Which of the following is not a zero of the polynomial shown below?
f(x)=x^4-x^3-42x^2+16x+160

A. -4

B. -2

C. 1

D. 2.5

Question

Which of the following is not a zero of the polynomial shown below?
f(x)=x^4-x^3-42x^2+16x+160

 
      A. -4

      B. -2

      C. 1

      D. 2.5

anonymous · Answer

Are you sure this equation is right?  Graphing this equation gives four roots that are not rational numbers.  I get -5.8 -1.9 2.2 and 6.5

anonymous · Answer

oops i just double checked. the first variable is 2x^4 no x^4

anonymous · Answer

Are you allowed a graphing calculator?  that is by far the easiest way to sovle this.

anonymous · Answer

my school gave me one but without instructions for anything so its kind of worthless to me

anonymous · Answer

what kind is it?  the other way to solve this is with polynomial division, which works but takes time.

anonymous · Answer

can you please just do it how you did it originally?

anonymous · Answer

I used a calculator to graph the eqation and used the zero function to trace the graph.  That working depends on what kind of calculator you have.

anonymous · Answer

can you do it for the new equation too?

anonymous · Answer

Yes, but that doesn't help you understand the subject.

anonymous · Answer

well i really need this question answered. its just for my very last assignment of the semester. I don't exactly need to understand because we are never touching this again. i just need A B C or D

anonymous · Answer

C

anonymous · Answer

thanks