Question

Can someone please explain if the value 5 is an upper bound for the zeros of the function f(x)=x^4+x^3-11x^2-9x+18 ?

Answer 1

hi my name is judy I meant help

Answer 2

can you help me judy?

Answer 3

@ali1029 do you mean if the highest degree is ?

Answer 4

well the question is

Answer 5

Take the coefficients of x^4+x^3-11x^2-9x+18 and do a synthetic division by 5.

Look at the result and notice the signs of the coefficients of both the quotient and the remainder.

If they are all the same sign, then value 5 is the upper bound for the zeros of the function.

Answer 6

thank you so much @ranga :)

Answer 7

@ranga I got all positive numbers; 1,6,14,116,642 so the answer would be true? I'm just not sure if i did the synthetic division correctly. do you mind double checking my work? :)

Answer 8

I am also getting all positive numbers and so the answer is true.

Answer 9

yes, thank you! :) can you check my newest question? its dealing with lower bounds and I dont know how to work with those!