 # Starter nth term rule 10 multiple choice questions

• Slides: 17 Starter nth term rule 10 multiple choice questions What is the nth term of 2 , 5, 8, 11, 14 ? 2 n 2 n + 3 3 n - 1 3 n + 2 What is the nth term of 1, 6, 11, 16, 21? n+5 5 n - 4 1 n + 5 5 n + 1 What is the nth term of 4, 10, 16, 22, 28? 2 n + 2 4 n + 6 6 n + 4 6 n - 2 What is the nth term of-2, 5, 12, 19, 26? 7 n - 9 -2 n + 7 7 - 2 n 7 n - 3 What is the nth term of 20 , 18, 16, 14, 12 ? -2 n 20 – 2 n 2 n + 18 22 - 2 n What is the nth term of 4 , -1, -6, -11, -16 ? 4 - 5 n 9 - 5 n 4 n - 5 -5 n What is the nth term of 9 , 6, 3, 0, -3 ? -3 n 12 - 3 n 9 n - 3 9 - 3 n What is the nth term of 2 , 2. 5, 3, 3. 5, 4? 0. 5 n 2 n + 0. 5 n÷ 2 0. 5 n + 1. 5 What is the nth term of 10 , 12. 5, 17. 5, 20 ? 7. 5 n + 2. 5 + 7 2. 5 n + 7. 5 10 + 2. 5 What is the nth term of. The problem-1, here is that sequence 5, 15 , 29, the 47? doesn’t go up or down in nice equal steps, the steps get bigger and bigger each time. A) B) None of these Do we give up? Nope, lets look at how to 6 n - 7 find the nth term of these sequences. C) -1 n + 6 D) 6 - 1 n -1 5 6 15 10 4 29 14 4 47 18 4 Because the second difference is the same, we call the sequence quadratic, and we know the equation will have n 2 in it. -1 5 6 15 10 4 29 14 47 18 4 4 4÷ 2=2 Sequence has 2 n 2 term -1 5 15 29 2 n 2 2 8 18 32 subtract -3 -3 Sequence is 2 n 2 - 3 5 14 9 29 15 6 50 21 6 77 27 6÷ 2=3 Sequence has 3 n 2 6 term 5 14 29 50 3 n 2 3 12 27 48 subtract 2 2 Sequence is 3 n 2 + 2 Stage One Answers 1) 2) 3) 4) 5) 2 n 2+3 3 n 2 -2 2 n 2 + 4 n 2 -1 4 n 2 4 13 9 26 13 4 43 17 4 64 21 4÷ 2=2 Sequence has 2 n 2 4 term 2 n 2 4 2 13 8 26 18 43 32 subtract 2 5 8 11 This sequence is 3 n - 1 Sequence is 2 n 2 + 3 n - 1 Stage Two Answers 1) 2) 3) 4) 5) 3 n 2 + 2 n + 1 4 n 2 + 3 n - 4 n 2 + 4 n + 2 2 n 2 + 5 n + 1 4 n 2 - 2 n