Question

The graphs of the functions f and g are lines, as shown above. If $a=f\left(2\right)$, find the value of $g(a+1)$.

• A. $1.5$
• B. $2$
• C. $3$
• D. $4$
• E. $4.5$

Answer 1

Answer: (C)

$3$

Use the graph to find $f\left(4\right)$ as follows. First, go to $x=4$ on the x-axis. Next, go vertically up until you reach the line for the function f. Finally, go over horizontally to find the y-value for that point (see the graph below).
You should see that when $x=4$, the y-value of function f is $2$. Since $a=f\left(4\right)$, we know that $a=2$ and we need to find $g\left(2\right)$. Repeat the process, now using the line for the function g. You will see that $g\left(2\right)=3$.