Question

Given the recursive formula below, what are the first 4 terms of the sequence?

image

Question 3 options:


A)


17, 19, 21, 23


B)


17, –6, –3, 0


C)


17, 13, 9, 5


D)


17, 15, 13, 11

Answer 1

D)

17,15,13,11

Explanation:

From the formula

`f(n) = f(n - 1) - 2 \\ f1 = 17 \\`

• we can deduce the next three terms as follows:
• 
  `f(2) = f(2 - 1) - 2 \\ f(2)= f(1) - 2 \\ f(2) = 17 - 2 \\ f(2) = 15\\`
• 
  `f(3) = f(3 - 1) - 2 \\ f(3)= f(2) - 2 \\ f(3) = 15 - 2 \\ f(3) = 13\\`
• 
  `f(4) = f(4 - 1) - 2 \\ f(4)= f(3) - 2 \\ f(4) = 13 - 2 \\ f(4) = 11\\`
• Hence the sequence is; 17, 15, 13, 11,...