Questions: Question 8 of 14
-11
Divide the polynomials by either long division or synthetic division.
(x^3+2x^2-4x-8) / (x+2)
Indicate the quotient, Q(x), and the remainder, r(x), in the equation
P(x) / d(x) = Q(x) + r(x) / d(x)
where P(x) = x^3+2x^2-4x-8 and d(x) = x+2.
Q(x) =
r(x) =
Transcript text: Question 8 of 14
$-11$
Divide the polynomials by either long division or synthetic division.
\[
\left(x^{3}+2 x^{2}-4 x-8\right) \div(x+2)
\]
Indicate the quotient, $Q(x)$, and the remainder, $r(x)$, in the equation
\[
\frac{P(x)}{d(x)}=Q(x)+\frac{r(x)}{d(x)}
\]
where $P(x)=x^{3}+2 x^{2}-4 x-8$ and $d(x)=x+2$.
\[
Q(x)=
\]
\[
r(x)=
\]
Solution
Solution Steps
To solve the problem of dividing the polynomial \( P(x) = x^3 + 2x^2 - 4x - 8 \) by \( d(x) = x + 2 \), we can use synthetic division. Synthetic division is a simplified form of polynomial division, particularly useful when dividing by a linear factor. The steps involve using the root of the divisor (in this case, -2) and performing operations on the coefficients of the dividend polynomial to find the quotient and remainder.
Step 1: Polynomial Division Setup
We are tasked with dividing the polynomial \( P(x) = x^3 + 2x^2 - 4x - 8 \) by the linear polynomial \( d(x) = x + 2 \). We will use synthetic division to perform this operation.
Step 2: Perform Synthetic Division
Using the root of the divisor \( d(x) \), which is \( -2 \), we apply synthetic division to the coefficients of \( P(x) \):
Coefficients of \( P(x) \): \( [1, 2, -4, -8] \)
Root: \( -2 \)
The synthetic division process yields:
Quotient coefficients: \( [1, 0, -4] \)
Remainder: \( 0 \)
Step 3: Express the Results
From the synthetic division, we can express the results as follows:
The quotient \( Q(x) \) is given by the polynomial formed from the coefficients:
\[
Q(x) = 1x^2 + 0x - 4 = x^2 - 4
\]
The remainder \( r(x) \) is:
\[
r(x) = 0
\]
Final Answer
Thus, we can summarize the results of the division:
\[
Q(x) = x^2 - 4
\]
\[
r(x) = 0
\]
The final boxed answers are:
\[
\boxed{Q(x) = x^2 - 4}
\]
\[
\boxed{r(x) = 0}
\]