Given the formula for an arithmetic sequence f(9) = f(8) + 4 written using a recursive formula, write the sequence using an arithmetic explicit formula.

f(9) = f(1) + 1
f(9) = f(1) + 4
f(9) = f(1) + 8
f(9) = f(1) + 32

The answer is option d

Step-by-step explanation:

  The given formula is for arithmetic sequence is

  f(9) = f(8) + 4

  By using the formula an = a +(n-1)d

  Where a is the first term and d is the common difference and n is the nth

  term

  ∵ By substituting in the main equation we get

   a + 8d = a +7d +4

   d = 4

 So by analyzing the options we get answer as option d

   f(9)  =  f(1) + 32

   a +8d = a +32

   8×d =32

   8×4 = 32

   32 = 32

  ∴The answer is option d

180

step-by-step explanation: