1.4.2

Index Notation

Test yourself

Powers (Indices)

Powers tell us how many times to use a number in multiplication.

Illustrative background for 5<sup>n</sup> means n copies of 5 multiplied togetherIllustrative background for 5<sup>n</sup> means n copies of 5 multiplied together ?? "content

5n means n copies of 5 multiplied together

  • 5n is called ‘5 raised to the power of n’

Roots

Roots are the opposite of powers.

Illustrative background for Square rootIllustrative background for Square root ?? "content

Square root

  • √25 means the number that squares to give 25 and so is +5 or -5 which we write as ±5.
    • There will always be a positive and a negative square root.
Illustrative background for Cube rootIllustrative background for Cube root ?? "content

Cube root

  • 3√125 means the number that cubes to give 125 and so is 5.
    • Note that (-5)3 = -125 so there is only one cube root.
Illustrative background for n<sup>th</sup> rootIllustrative background for n<sup>th</sup> root ?? "content

nth root

  • n√x means the number that when raised to the power of n gives x.
    • There will be positive and negative roots if n is even, and only a positive root if n is odd.

Jump to other topics

1Numbers

2Equations, Formulae & Identities

3Sequences, Functions & Graphs

4Geometry

5Vectors & Transformation Geometry

6Statistics & Probability

Unlock your full potential with Seneca Premium

  • Unlimited access to 10,000+ open-ended exam questions

  • Mini-mock exams based on your study history

  • Unlock 800+ premium courses & e-books

Get started with Seneca Premium