what is the recursive formula for the sequence... 15,26,48,92..

Question

amistre64 · Answer

well, we can start by seeing if it linear, quadratic or other by finding the difference between terms until they are alike

anonymous · Answer

f(n+1)=f(n)*2-4

amistre64 · Answer

92     48        26
-48    -26      -15
----   ----   -----  ; it aint linear
  44      22       11

  44    22
-22   -11
----  ----  ; and it aint quadratic
  22     11

amistre64 · Answer

it might be exponential or logistic; but i aint got that far ....

amistre64 · Answer

Ente might have it; i havent tried :)

anonymous · Answer

lets see...
f(0)=15
f(1)=15*2-4=30-4=26 check
f(2)=26*2-4=52-4=48 check
f(3)=48*2-4=96-4=92 check

so f(n+1)=f(n)*2-4 is a correct recursive formula for the problem

amistre64 · Answer

yay!! :)

anonymous · Answer

correct ente

amistre64 · Answer

either you have a good eye for it; or you know something more....

anonymous · Answer

just tried around a bit... loved that sort of question in school ^^ often harder to get an explicit formula though ;)