Manipulating Surds (Edexcel GCSE Maths): Flashcards

Irrational square roots that can't be written as fractions

Surds give exact values, decimals are approximations

$\sqrt{a \times b}$

$b$

$\sqrt{a/b}$

No, cannot be combined or simplified

No, this is a common mistake to avoid

$a^2 + 2a\sqrt{b} + b$

$a^2 - b$

Removing square roots from the bottom of fractions

Multiply top and bottom by $\sqrt{b}$

Circle calculations with $\pi$, problems with surds

Preserve mathematical precision, prevent compounding errors