Answer
If the equation $y = F(x)$ is changed to $y = c \cdot F(x)$, for some constant c, the graph of $y = F(x)$ will be stretched or shrank vertically.
Work Step by Step
To be more precise,
if $c \gt 1$ or $|c| \gt 1$, the graph will be stretched vertically.
if $0 \lt c \lt 1$ or $0 \lt |c| \lt 1$, the graph will be shrank vertically.
if $-1 \lt c \lt 0$, the graph will be shrank vertically and reflected across the x-axis.
if $c = -1$, the graph will be same without any stretching or shrinking but being reflected across the x-axis only.
if $c \lt -1$, the graph will be stretched vertically and reflected across the x-axis.
