Here I introduce you to, two other methods of proof. Proof by exhaustion and proof by deduction.

Example to try

  1. Show that the cube numbers of 3 to 7 are multiples of 9 or 1 more or 1 less than a multiple of 9.
  2. Show that all cube numbers are multiples of 9 or 1 more or 1 less than a multiple of 9.