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Fractional and Negative Indices
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What indices are telling you

What indices are telling you

One helpful way to calculate a−m/na^{-m/n}a−m/n is:

  • Negative sign: take the reciprocal.
  • Denominator nnn: take the nnnth root.
  • Numerator mmm: raise to the power mmm.

So

a−m/n=1(an)m=1amn a^{-m/n}=\frac{1}{(\sqrt[n]{a})^m}=\frac{1}{\sqrt[n]{a^m}} a−m/n=(na​)m1​=nam​1​

Example:

32−2/5=1(325)2=122=14 32^{-2/5}=\frac{1}{(\sqrt[5]{32})^2}=\frac{1}{2^2}=\frac{1}{4} 32−2/5=(532​)21​=221​=41​

Fractional and Negative Indices Lesson

  1. IGCSE
  2. /Maths
  3. /Fractional and Negative Indices

Step-by-step lessons on Edexcel IGCSE Maths Fractional and Negative Indices. Each one builds up to exam-style questions. Build confidence with the shared Foundation-tier content first, since roughly 40% of Higher-tier marks are targeted at the grades 4–5 boundary that both tiers have in common.

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