Arithmetic Progressions (Cambridge International A-Level Mathematics)

Arithmetic Sequences

Arithmetic progressions

What are arithmetic progressions?

• In an arithmetic progression(also called 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 progression $u_{n}=a+(n-1)d$

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

Exam Hint

• The formula is given in the formula booklet
• If you know two terms in an arithmetic sequence you can find a and d using simultaneous equations.

Worked Example