Surds Flashcards

An irrational number that cannot be simplified to remove a square root (or cube root, etc.).

To simplify a surd, factorise the number under the square root into a product of a square number and another number, then simplify.

√50 = √(25 × 2) = 5√2.

The process of removing a surd from the denominator of a fraction by multiplying numerator and denominator by a suitable value.

1/√2 = (1/√2) × (√2/√2) = √2/2.

You can only add or subtract surds if they have the same value under the square root (like terms).

2√3 + 3√3 = 5√3.

To multiply surds, multiply the numbers inside the square roots together, then simplify if possible.

√2 × √3 = √6.

√a × √b = √(a × b), as long as a and b are positive.