Why is 10\sqrt{10}10 a surd but 16\sqrt{16}16 is not?
A
The root-index equivalences are an=\sqrt[n]{a}=na= a1na^{\frac{1}{n}}an1 and amn=\sqrt[n]{a^m}=nam= amn\boxed{a^{\frac{m}{n}}}anm.
B
10\sqrt{10}10 is irrational, while 16=4\sqrt{16}=416=4 is rational.
C
x3\sqrt{x^3}x3 or (x)3(\sqrt{x})^3(x)3.
D
The numerator gives the power.
1.2.2 Surds Flashcards
Flashcards for OCR A Level Maths 1.2.2 Surds, covering the key formulae, methods and definitions you need to recall for Paper 1, Paper 2 and Paper 3. 25 cards, matched to the OCR A Level Maths (H240) specification. Recall questions account for roughly 50% of marks at A Level Maths, so these target the marks you can secure before the paper starts.