Answered

Select the correct answer.

Consider this absolute value function:

[tex]\[ f(x) = |x + 8| \][/tex]

How can function [tex]\( f \)[/tex] be written as a piecewise function?

A. [tex]\[ f(x) = \left\{ \begin{array}{ll} x + 8, & x \geq -8 \\ -x - 8, & x \ \textless \ -8 \end{array} \right. \][/tex]

B. [tex]\[ f(x) = \left\{ \begin{array}{ll} x + 8, & x \geq -8 \\ -x + 8, & x \ \textless \ -8 \end{array} \right. \][/tex]

C. [tex]\[ f(x) = \left\{ \begin{array}{ll} x + 8, & x \geq 8 \\ -x + 8, & x \ \textless \ 8 \end{array} \right. \][/tex]

D. [tex]\[ f(x) = \left\{ \begin{array}{ll} x + 8, & x \geq 8 \\ -x - 8, & x \ \textless \ 8 \end{array} \right. \][/tex]



Answer :

To write the absolute value function [tex]\(f(x) = |x + 8|\)[/tex] as a piecewise function, we need to consider the definition of the absolute value function. The absolute value of a number [tex]\(a\)[/tex] is defined as follows:

[tex]\[ |a| = \begin{cases} a & \text{if } a \geq 0 \\ -a & \text{if } a < 0 \end{cases} \][/tex]

In this case, our function is [tex]\( f(x) = |x + 8| \)[/tex]. We need to consider two cases based on the expression inside the absolute value sign [tex]\(x + 8\)[/tex]:

1. [tex]\( x + 8 \geq 0 \)[/tex] which simplifies to [tex]\( x \geq -8 \)[/tex]
2. [tex]\( x + 8 < 0 \)[/tex] which simplifies to [tex]\( x < -8 \)[/tex]

For [tex]\( x \geq -8 \)[/tex]:
[tex]\[ |x + 8| = x + 8 \][/tex]
So, [tex]\( f(x) = x + 8 \)[/tex].

For [tex]\( x < -8 \)[/tex]:
[tex]\[ |x + 8| = -(x + 8) = -x - 8 \][/tex]
So, [tex]\( f(x) = -x - 8 \)[/tex].

Putting these together, we have the piecewise function:
[tex]\[ f(x) = \begin{cases} x + 8 & \text{if } x \geq -8 \\ -x - 8 & \text{if } x < -8 \end{cases} \][/tex]

Let’s check the options provided:

A. [tex]\( f(x) = \left\{\begin{array}{ll}x+8, & x \geq -8 \\ -x-8, & x<-8\end{array}\right. \)[/tex]

B. [tex]\( f(x) = \left\{\begin{array}{ll}x+8, & x \geq -8 \\ -x+8, & x<-8\end{array}\right. \)[/tex]

C. [tex]\( f(x) = \left\{\begin{array}{ll}x+8, & x \geq 8 \\ -x+8, & x<8\end{array}\right. \)[/tex]

D. [tex]\( f(x) = \left\{\begin{array}{ll}x+8, & x \geq 8 \\ -x-8, & x<8\end{array}\right. \)[/tex]

The correct piecewise function is:

A. [tex]\( f(x) = \left\{\begin{array}{ll}x+8, & x \geq -8 \\ -x-8, & x<-8\end{array}\right. \)[/tex]

So, the correct answer is:

[tex]\[ \boxed{A} \][/tex]