Answer
Option (c)
Work Step by Step
RECALL:
The function $y=a \cdot f(x)$ where $a \gt 1$, involves a vertical compression by a factor of $a$ of the parent function $f(x)$.
A vertical compression by a factor of$a$ means that for the same $x$ value, the value of $f(x)$ is multiplied by $a$.
The given function is $y=2(fx)$.
The value of $a$ is $2$.
Thus, the function involves a vertical compression by a factor of $2$ of the parent function.
This means that the y-value of $y=2f(x)$ is two times the y-value of $y=f(x)$.
Therefore, if $(1, 3)$ is on the graph of $y=f(x)$, then the point $(1, 6)$ is on the graph of $y=2f(x)$.
The answer is Option (c).