Horizontal and vertical scaling

Let $c$ be a fixed positive number.

#[Horizontal scaling][Escalamiento horizontal]#

• If $c \gt 1,$ then replacing $x$ by the quantity $(cx)$ compresses the graph in the $x$-direction by a factor of $c.$ (Press the button to see it happen when $c = 2$.)
• If $c \lt 1,$ then replacing $x$ by the quantity $(cx)$ stretches the graph in the $x$-direction by a factor of $1/c.$ (Press the button to see it happen when $c = 1/2$.)

#[Vertical scaling][Escalamiento vertical]#

• If $c \gt 1,$ then replacing $f(x)$ by $cf(x)$ stretches the graph in the $y$-direction by a factor of $c.$ (Press the button to see it happen when $c = 2$.)
• If $c \lt 1,$ then replacing $f(x)$ by $cf(x)$ compresses the graph in the $y$-direction by a factor of $1/c.$ (Press the button to see it happen when $c = 1/2$.)