How do you write y=|x+1|-4y=|x+1|4 as a piecewise function?

1 Answer
Jan 16, 2018

color(blue)(|x+1| - 4 = { x+1, if x>= (-1)})

color(blue)(|x+1| - 4 = { -x-1, if x< (-1)})

Explanation:

Given:

color(red)(y=f(x)=|x+1|-4)

We draw the graph of this function first

enter image source here

color(green)(Step.1)

We find the boundary line first.

Later, once we find the "Piece-wise Functions", we can graph those as well and compare the graphs.

We can accomplish this process by setting what is inside absolute value to ZERO, and then solving for color(red)x.

So, when

x+1 =0

we get

color(blue)(x = (-1))

color(green)(Step.2)

When (x+1) is Positive, we just consider the expression as it is,

but if (x+1) is Negative, we must negate the whole expression

color(green)(Step.3)

Hence,

our required Piece-wise Functions are

color(blue)(|x+1| - 4 = { x+1, if x>= (-1)})

color(blue)(|x+1| - 4 = { -x-1, if x< (-1)})

We will graph the Piece-wise Functions below:

enter image source here

Hope this helps.