Question

use the graphs of f and g to find (f + g)( - 1). (f + g)( - 1)=4

Explanation:

Step1: Recall function - sum definition

By the definition of the sum of two functions, $(f + g)(x)=f(x)+g(x)$. So, $(f + g)(-1)=f(-1)+g(-1)$.

Step2: Find $f(-1)$ from the graph

Looking at the graph of $y = f(x)$, when $x=-1$, the $y$ - value of the function $f$ is $f(-1)=5$.

Step3: Find $g(-1)$ from the graph

Looking at the graph of $y = g(x)$, when $x = - 1$, the $y$ - value of the function $g$ is $g(-1)=-1$.

Step4: Calculate $(f + g)(-1)$

Substitute $f(-1)=5$ and $g(-1)=-1$ into $(f + g)(-1)=f(-1)+g(-1)$. Then $(f + g)(-1)=5+( - 1)=4$.

Answer:

$4$