An index is the number which is at the top right hand corner of a figure which denotes a power. The power of a number is how many times the number is multiplied by itself. For example:
22 = 2 × 2 = 4
43 = 4 × 4 × 4 = 64
34 = 3 × 3 × 3 × 3 = 81
When using indices you should remember the following things:
- Multiplying adds the powers:
nx × ny = nx+y
- Division subtracts the powers:
nx ÷ ny = nx-y
- A negative index means the number is reciprocated:
n-x = 1 / nx
- For fractional indices, the numerator is the power of the base number and the denominator is the root of this number:
nx/y = y
nx
- n1 = n
- n0 = 1
