If x = −2 is a zero of the polynomial function f(x) = 2x3 + 9x2 − 8x − 36, which of the following is another zero of f(x)?

Select one:

Ax = 8
Bx = 4
Cx = 3
Dx = 2

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Verified Answer :

bomeigang bomeigang · Answer 1 · 2016-12-27T22:59:58-05:00

f(x) = 2*x^3 + 9x^2 -8x - 36
= 2x ( x^2 - 4) + 9( x^2 -4)
= (2x + 9)(x^2 - 4)
= (2x + 9)(x-2)(x+2)

x = 2, -2 , -9/2

ans. = d. x=2

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flightbath flightbath · Answer 2 · 2018-11-21T05:05:16-05:00

Answer: Option d is correct that is x=2 is the another zero of the given polynomial

Explanation:

We have been given the polynomial \(2x^3+9x^2-8x-36\)

Zero of any polynomial is the point where the value of function is zero

Here we are given one zero at x=-2 if we substitute the value x=-2 in the given polynomial we will get zero

Now to find other point where we will get the solution or we will get zero

First we substitute x=8 in the given polynomial we will get

\(2(8)^3+9(8)^2-8(8)-36\\\\=1500 eq0\) Hence, not the zero of given polynomial

Similarly, when we substitute x=4 in the given polynomial we will get

\(2(4)^3+9(4)^2-8(4)-36\\\\=204 eq0\) Hence, not the zero of given polynomial

Similarly, substitute x=3 in the given polynomial we will get

\(2(3)^3+9(3)^2-8(3)-36\\\\=75 eq0\) Hence, not the zero of given polynomial

Substitute x=2 in the given polynomial we will get

\(2(2)^3+9(2)^2-8(2)-36\\\\=0\) Hence, the zero of the polynomial

Therefore Option d is correct.