Formulas & tables/Mathematics/Special products/Square of a difference

Square of a difference

(a−b)2=a2−2ab+b2(a-b)^2=a^2-2ab+b^2

Result unit: — (expression)

What it describes

The square of the difference of two expressions.

Symbols

a,ba, b
arbitrary expressions (numbers)

Where it comes from

Like the square of a sum, but the middle term is negative (−2ab-2ab).

When to use it

Expanding squares of differences.

Example

Expand (x−2)2(x-2)^2.
Substitutiona=xa=x, b=2b=2.
Resultx2−4x+4x^2-4x+4.

Related formulas

Square of a sum Difference of squares

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