Suppose [tex]$f(x)=x^2$[/tex] and [tex]$g(x)=(4x)^2$[/tex]. Which statement best compares the graph of [tex][tex]$g(x)$[/tex][/tex] with the graph of [tex]$f(x)$[/tex]?

A. The graph of [tex]$g(x)$[/tex] is horizontally compressed by a factor of 4.
B. The graph of [tex][tex]$g(x)$[/tex][/tex] is horizontally stretched by a factor of 4.
C. The graph of [tex]$g(x)$[/tex] is shifted 4 units to the right.
D. The graph of [tex]$g(x)$[/tex] is vertically stretched by a factor of 4.



Answer :

Let's compare the functions [tex]\( f(x) = x^2 \)[/tex] and [tex]\( g(x) = (4x)^2 \)[/tex].

1. Start by analyzing the written functions.

- [tex]\( f(x) = x^2 \)[/tex] is a basic quadratic function, which represents a standard parabola opening upwards with its vertex at the origin (0, 0).
- [tex]\( g(x) = (4x)^2 \)[/tex] can be rewritten as [tex]\( g(x) = 16x^2 \)[/tex].

2. Next, look at the transformation that [tex]\( g(x) \)[/tex] represents.

We can rewrite [tex]\( g(x) \)[/tex] to identify the coefficient inside the function:
[tex]\[ g(x) = (4x)^2 \][/tex]

Simplify the expression inside the parentheses:
[tex]\[ g(x) = 16x^2 \][/tex]

3. Recognizing the transformation involves understanding how the term [tex]\( (4x) \)[/tex] affects the graph. The factor inside the function (here, the 4) changes the graph's horizontal scaling:

- If we replace [tex]\( x \)[/tex] with [tex]\( cx \)[/tex] in a function [tex]\( f(x) \)[/tex], where [tex]\( c>1 \)[/tex]:
- It horizontally compresses the graph by a factor of [tex]\( c \)[/tex].
- So, in [tex]\( g(x) = (4x)^2 \)[/tex]:
- The [tex]\( 4 \)[/tex] inside the parentheses denotes a horizontal compression by a factor of 4.

4. Finally, examine the given choices to find the correct description of [tex]\( g(x) \)[/tex] with respect to [tex]\( f(x) \)[/tex]:

- A. The graph of [tex]\( g(x) \)[/tex] is horizontally compressed by a factor of 4.
- B. The graph of [tex]\( g(x) \)[/tex] is horizontally stretched by a factor of 4.
- C. The graph of [tex]\( g(x) \)[/tex] is shifted 4 units to the right.
- D. The graph of [tex]\( g(x) \)[/tex] is vertically stretched by a factor of 4.

Since we determined [tex]\( g(x) = (4x)^2 \)[/tex] involves a horizontal compression by a factor of 4, the correct statement is:

A. The graph of [tex]\( g(x) \)[/tex] is horizontally compressed by a factor of 4.