College Algebra (10th Edition)

RECALL: The graph of the function $y=f(ax)$ yields one of the following transformations of the parent function $f(x)$: (i) horizontal compression when $a\gt 1$; or (ii) horizontal stretch when $0 \lt a \lt 1$ The given function involves a horizontal compression by a factor of $4$, which means that $a=4$. Thus, the equation of the function is: $y=f(4x)$ Therefore, the answer is Option (a).