Sequences (Nth term)

• How to find nth term

  nth term = a + (n-1) d
• Sum of first "n" terms

  $S_n=$$\frac{1}{2}[2a+(n-1)d]$

  Sum of first terms = half of n [2 x first term + (term number e.g. 1st - 1) x common difference]

  a = first term

  b = common difference
• In sequencing equations:

  a =

  d =

  n =

  a = first term

  d = common difference

  n = nth term (so 1st term, second term etc.)