Arithmetic Sequences (Edexcel IAL Maths)

Spec point — 4.2

Arithmetic sequences

What do I need to know about arithmetic sequences?

• In an arithmetic sequence, the difference between consecutive terms in the sequence is constant

• That constant difference is known as the common difference of the sequence

• You need to know the n^thterm formula for an arithmetic sequence $u_{n}=a+(n-1)d$

  • a is the first term
  • d is the common difference

Exam Hint If you know two terms in an arithmetic sequence you can find a and d using simultaneous equations.

Worked Example