Edexcel IGCSE Maths 复习笔记 2.4.3 Difference of Two Squares

What is the difference of two squares?

• A “Difference Of Two Squares” is any expression in the form p² – q²

Why is it so important?

• It comes up a lot – recognising it can save a lot of time

How does it factorise?

• p² – q² can always be factorised in the same way:p² – q² = (p + q)(p – q)

  (Try multiplying it out to see why…)