Question
A rare bacterial culture is being grown in a lab. As the days progress, the cells multiply and grow.
After 1 day, there is only 1 cell.
After 2 days, there are 9 cells.
After 3 days, there are 20 cells.
After 4 days, there are 34 cells.
Which recursive equation represents the pattern?
After 1 day, there is only 1 cell.
After 2 days, there are 9 cells.
After 3 days, there are 20 cells.
After 4 days, there are 34 cells.
Which recursive equation represents the pattern?
Answers
PsyDAG
What are your choices?
Steve
an=an-1+3n
an=an-1+(n+2)
an=an-1+3(n+2)
an=an-1+(3n+2)
I thought it was the last one but am not sure and am trying to help my grandson.
an=an-1+(n+2)
an=an-1+3(n+2)
an=an-1+(3n+2)
I thought it was the last one but am not sure and am trying to help my grandson.
Steve
well, the amounts added are 8,11,14
They differ by 3, so it will look like
a(n) = a(n-1) + 3n + ?
3n looks like 3,6,9, so we have
a(n) = a(n-1) + 3(n-1)+5 = a(n-1)+(3n+2)
so you are correct
They differ by 3, so it will look like
a(n) = a(n-1) + 3n + ?
3n looks like 3,6,9, so we have
a(n) = a(n-1) + 3(n-1)+5 = a(n-1)+(3n+2)
so you are correct
Steve
thank you