Absolute value graphs
(Transformation)
Refer to Khan academy: Absolute value graphs
To understand this idea, need to review the previous knowledge of Transformation
of graphs, including translation
, rotation
, reflection
, dilation
. Also need to know the scale factor
of dilation.
For a simplest form of an absolute value equation
, it can be represented as:
And the most common use for this idea, is in Quadratic
:y=x²
And the general form of an absolute value equation
:
In the equation,
- The sign of
a
, negative sign ofa
means the graph is flipped byx-axis
. a
is thescale factor
of the graph, equals tog'(x)÷g(x)
.h
is distance ofmoving right
, should be subtracted byx
.k
is distance ofmoving up
, should be added byy
.
Notice that:
The h
is confusing sometime ----
it's the distance of moving right,
and should be subtracted from x
.
Subtracted ,subtracted, subtracted!
For understanding why is it subtracted, review this Khan lecture in 2 minutes.
Simplest equation y = |x|
Shifted(Translated) equation y = |x + h| + k
Flipped(Reflected) version y = - |x|
It’s only flipping by the x axis
.