EDEXCEL GCSE Foundation Maths - What are Indices?
What are Indices?
Indices (also known as exponents) are a shorthand way of representing repeated multiplication.
The Basics
- Base: The number being multiplied.
- Index (or Exponent): The number of times the base is multiplied by itself.
Example:
* 2^3
means 2 multiplied by itself 3 times: 2 x 2 x 2 = 8
Types of Indices
- Square: An index of 2. Example:
3^2 = 3 x 3 = 9
- Cube: An index of 3. Example:
2^3 = 2 x 2 x 2 = 8
- Other Indices: Indices can be any whole number. Example:
5^4 = 5 x 5 x 5 x 5 = 625
Important Rules
- Anything to the power of 1 is itself:
5^1 = 5
- Anything to the power of 0 is 1:
7^0 = 1
- Negative indices:
a^-n = 1/a^n
(a cannot be 0)
- Fractional indices:
a^(1/n) = n?a
(where n is a positive integer)
Examples
- Calculate 4^3:
4^3 = 4 x 4 x 4 = 64
- Simplify 2^-2:
2^-2 = 1/2^2 = 1/4
- Calculate 8^(1/3):
8^(1/3) = ?8 = 2
Key Points
- Indices are a fundamental concept in mathematics.
- Understanding them is crucial for further study in algebra, geometry, and calculus.
- Practice is key to mastering indices!
Try These!
- Calculate 3^4.
- Simplify 5^-1.
- Calculate 16^(1/2).
Answers
- 81
- 1/5
- 4
Next Steps
- Explore the rules of indices in more detail.
- Learn about operations involving indices (addition, subtraction, multiplication, division).
- Practice solving problems involving indices.