**Arithmetic** - Found by adding a common number to the first term and then to the second term etc. Find this common
- term by subtracting a 2nd number from 1st etc. Be sure to spot the pattern.

**To find the Nth term** - – use a formula

- Where
- a
_{1} = first term of sequence - a
_{n} = the term you wish to find - d= common difference
- n – place position of the
- term IE Find term 20 – n = 20

**a**_{n}= a_{1} + d(n-1)
**Geometric Sequences**
- Found by multiplying a common number from 1 term to the next. For example multiplying 3 by the first term and then multiplying 3 by the
- first number etc. Find the common ratio by problem solving and spotting the pattern.

Can do this by dividing the 2nd term by the first term – this is called the common ratio. Can use decimals or fractions.

**To find the Nth term – use a formula** - Use exponents ( r = common ratio)

a

_{n }= a

_{1} x r

^{n-1}