Arithmetic sequence (gr10 lesson)

• Arithmetic sequence


  Also known as arithmetic progression
• Arithmetic sequence


  • Has a common number that is added to get the next term
  • The common number is found by subtracting the previous term from the current term
• Common difference


  The fixed number that is added to get the next term in an arithmetic sequence
• a1, a2, a3, a4


  The first, second, third, fourth terms in an arithmetic sequence
• Arithmetic mean


  The average found between two extremes in an arithmetic sequence
• Finding arithmetic mean


  1. Add the two extremes and divide by 2

  2. Use the formula: an = a1 + (n-1)d to find the common difference d, then insert the means between the extremes
• The sum of the first 100 counting numbers is 5050
• The sum of the first 150 counting numbers is 11,325
• Steps to find arithmetic mean between two numbers

  Illustrate the sequence with the two extremes

  2. Find the common difference using the formula

  3. Insert the means between the extremes