Answer & explanation!

4) is the opposite function of 3), and vice versa. Because f(x) =2x-1 and  its opposite f(x)=-2x+1. And we can see them both in pictures 3 and 4.

Step-by-step explanation:

A piecewise function is a function defined in a sequence of  intervals. The most known piecewise function is the modular function. (1st picture)

An opposite function is given by f(x)=-x of f(x)=x

The following pictures describe the following functions:

1) f(x)=-|2x|+2

2) f(x)= 2.34x-2.34 and f(x)= -2.34x-2.34

Notice how the second function express the opposite line, by the opposite angular coefficient.

3) f(x) =2x-1 and f(x)=-2x+1

4) f(x) = -2x+1 and f(x)=2x-1

Different intervals but the same functions are graphed in 3 and 4. So the graph of f(x)=2x-1 and its opposite f(x)=-2x-1