Problem

Use the factor theorem and synthetic division to decide whether the second polynomial is a factor of the first.
\[
-x^{3}+2 x-4 ; x+2
\]

Is $x+2$ a factor of $-x^{3}+2 x-4$ ?
Yes
No

Answer

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Answer

\(\boxed{\text{Yes}}\)

Steps

Step 1 :The Factor Theorem states that a polynomial \(f(x)\) has a factor \((x - k)\) if and only if \(f(k) = 0\).

Step 2 :To check if \((x + 2)\) is a factor of the polynomial \(-x^3 + 2x - 4\), we need to find the value of the polynomial when \(x = -2\) (since \(x + 2 = 0\) when \(x = -2\)).

Step 3 :Substitute \(x = -2\) into the polynomial: \(f(-2) = -(-2)^3 + 2*(-2) - 4 = -(-8) - 4 - 4 = 8 - 4 - 4 = 0\).

Step 4 :Since \(f(-2) = 0\), by the Factor Theorem, \((x + 2)\) is a factor of the polynomial \(-x^3 + 2x - 4\).

Step 5 :\(\boxed{\text{Yes}}\)

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