Find (f + g)(x). $\begin{array} { l }
f ( x ) = x ^ { 2 } - 2 x - 1 \
g ( x ) = - 3 x ^ { 2 } + x - 1
\end{array}$
A) $( f + g ) ( x ) = 4 x ^ { 4 } - 3 x ^ { 2 }$
B) $( f + g ) ( x ) = 2 x ^ { 2 } - x + 2$
C) $( f + g ) ( x ) = - 2 x ^ { 4 } - x ^ { 2 } - 2$
D) $( f + g ) ( x ) = 4 x ^ { 2 } - 3 x$
E) $( f + g ) ( x ) = - 2 x ^ { 2 } - x - 2$

Question

Find (f + g)(x).​​ $\begin{array} { l } 
f ( x ) = x ^ { 2 } - 2 x - 1 \
g ( x ) = - 3 x ^ { 2 } + x - 1
\end{array}$ ​ ​
A)​ $( f + g ) ( x ) = 4 x ^ { 4 } - 3 x ^ { 2 }$
B)​ $( f + g ) ( x ) = 2 x ^ { 2 } - x + 2$
C)​ $( f + g ) ( x ) = - 2 x ^ { 4 } - x ^ { 2 } - 2$
D)​ $( f + g ) ( x ) = 4 x ^ { 2 } - 3 x$
E)​ $( f + g ) ( x ) = - 2 x ^ { 2 } - x - 2$

Quizplus · Accepted Answer

To find $(f + g)(x)$, you add the corresponding coefficients of the same degree terms from $f(x)$ and $g(x)$. Adding $f(x) = x^2 - 2x - 1$ and $g(x) = -3x^2 + x - 1$ gives $(-2x^2 - x - 2)$, which matches choice E.

Find (F + G)(x) f(x)=x2−2x−1g(x)=−3x2+x−1\begin{array} { l } f ( x ) = x ^ { 2 } - 2 x - 1 \\g ( x ) = - 3 x ^ { 2 } + x - 1\end{array}f(x)=x2−2x−1g(x)=−3x2+x−1​

Find (F + G)(x) $\begin{array} { l } f ( x ) = x ^ { 2 } - 2 x - 1 \\g ( x ) = - 3 x ^ { 2 } + x - 1\end{array}$