Question

Write the recursive formula then determine the next term of 3,10,24,52

Answer 1

Answer:

• f[1] = 3
• f[n] = 2·f[n-1] +4
• 108

Step-by-step explanation:

We observe that first differences of the given numbers are ...

  10 -3 = 7

  24 -10 = 14

  52 -24 = 28

That is, each difference is 2× the previous one. This suggests an exponential relation that has a base of 2.

We notice that doubling a term doesn't give the next term, but gives a value that is 4 less than the next term. So, we can get the next term by doubling the previous one and adding 4.

Then our recursive relation is ...

  f[1] = 3 . . . . the first term

  f[n] = 2×f[n-1] +4 . . . . double the previous term and add 4

The next term is 2·52 +4 = 108.