A function can be written as piecewise function if it changes its behaviour ( increasing or decreasing ) about a point.
[tex]\begin{gathered} Thefunctionf\mleft(x\mright)=y=|x|changesitsbehaviourat|x|=0ie,x=0. \\ y=|x|=x,ifx<0=-x,ifx>0 \\ |x|=a\Rightarrow x=\pm a \end{gathered}[/tex]Here Here,
The given function is : y = 2|x| - 3
Here,
The function will change its behaviour when
| x | = 0
=> x = 0
Now,
If x < 0 , then ;
=> y = 2[–(x)] – 3
=> y = –2x – 3
=> y = – 2x – 3
If x ≥ 0 , then ;
=> y = 2(x) – 3
=> y = 2x – 3
=> y = 2x -3
Hence ,
y = – 2x – 3 , if x < 0
y = 2x - 3 , if x ≥ 0
[tex]f(x)=\begin{cases}-2x-3\text{ , if x < }0 \\ \\ 2x-3\text{ , if x }\ge0\end{cases}[/tex]