All lessons
|x|

Absolute Value Functions

The V-shape — reflections and shifts in one clean fold.

Interactive graph

Interactive Lab
Drag corner to resize ↘

Drag the sliders in the Desmos graph. Watch how each parameter reshapes the curve in real time.

Concepts

Parent V-Shape

VisualFold the line y=x in half along the y-axis — every negative output flips positive.

Algebray=∣x∣={xx≥0−xx<0y = |x| = \begin{cases} x & x \ge 0 \\ -x & x < 0 \end{cases}. Vertex at origin.

y=∣x∣y = |x|

Vertex Form

VisualDrag the red vertex — the V pivots around (h,k). a controls the opening steepness and direction.

Algebray=a∣x−h∣+ky = a|x-h| + k. Vertex at (h,k)(h,k). Opens up if a>0a>0, down if a<0a<0.

y=a∣x−h∣+ky = a|x-h| + k

Solving Equations

VisualTwo candidate solutions — one from each arm of the V. Always verify in the original.

Algebra∣x−h∣=d  ⟺  x−h=±d|x-h|=d \iff x-h = \pm d.

∣A∣=d  ⟹  A=±d|A| = d \implies A = \pm d

Key formulas

Absolute value parent
y=∣x∣y = |x|
Vertex at origin
Vertex form
y=a∣x−h∣+ky = a|x-h|+k
Vertex (h,k)
Split rule
∣A∣=d⇒A=±d|A|=d \Rightarrow A=\pm d
d ≥ 0 required

Finished reading?

Mark this lesson complete to update your mastery.

Quick practice

Full practice
easyabsolute value
Find the vertex of y=∣x−2∣+3y=|x-2|+3.
easyabsolute value
Evaluate ∣−7∣+∣4∣|-7| + |4|.
mediumabsolute value
Solve ∣2x−3∣=5|2x-3| = 5.
mediumabsolute value
Write y=∣x∣+2y=|x|+2 as a piecewise function.
hardabsolute value
Solve ∣x−3∣<2|x-3| < 2. Express as an interval.