Series and Induction

Proof by Induction

The principle of mathematical induction involves:

  • Proving a statement is true for (the basis case)
  • Proving that if you assume the statement is true for , then you can prove that it is also true for .

Much like dominoes falling, the proof for causes the proofs for to fall into place, proving the statement to be true for all positive integers .

Standard series

The following formulae can be used without proof:


  • The second and third formulae are given in the formula book.

Series can be manipulated in the following ways:

  • .

Method of differences

If the general term of a series can be written as , then:

The series won't always take this exact form; sometimes cancellations can happen two terms apart. When using the method of differences, make it clear what the cancellation pattern is.