a1" title="f(x)=\sqrt(x) \\ g(x)=\sqrt((4)/(5)x)" alt="f(x)=\sqrt(x) \\ g(x)=\sqrt((4)/(5)x)" align="absmiddle" class="latex-formula"> Identify a horizontal or vertical stretch or compression of the function f(x)=\sqrt(x) by observing the equation of the function g(x)=\sqrt((4)/(5)x)
A. A vertical compression by a factor of 5/4
B. A horizontal compression by a factor of 5/4
C. A horizontal stretch by a factor of 5/4
D. A vertical stretch by a factor of 5/4
Replacing x in f(x) by kx introduces a horizontal compression by a factor of k, or a stretch by a factor of 1/k. Here, we have k=4/5, so the curve is stretched horizontally by a factor of 5/4.
A relation is a <em>function</em> when there is exactly one output for each input. That is the case in this table, so the relation between the original price and sale price is a function.
