Dear All I have problem in formula ans it was solved Mr. Max , now i am
facing problem in Chart please do the needful .
I am mention the my problem and the formula given by Mr.Max .

In cell b1 my input value varies from 1-30
in e1 my input will be amount it varies assume 300000.
i want formula in a5 to show 0 and a6 as 1 so on till i get the input in b1
.. and in c5 i need a formula =$e$1*((2*(a5/$b$1)^2-(a5/$b$1)^4) till same as
in column based on the value in b1.
wish you all a very happy new year -2010 in advance



A B C D E F
G
1


2

3
Mr.Max solution is
Q1
In A5: =IF(ROWS($1:1)-1B$1,"",ROWS($1:1)-1)
Copy down to A35. A5:A35 will return the auto-serializing that I think you
seek, starting from zero till the max value that is specified for B1 (30).
The serializing terminates at the number that you input into B1.

Q2
In C5: =IF(A5="","",$E$1*((2*(A5/$B$1)^2-(A5/$B$1)^4)))
Copy down to C35. I merely bolted-on a front IF trap: =IF(A5="","", ...
to your formula as posted so that it returns correspondingly to the serial
numbers in A5:A35. Where the serial terminates, it returns blanks: "". I'm
guessing this is what you want to happen

Now my problem is
If i use chart ( Lines) what range
i have to select so that it changes automatically wrt to the no of months
without showing drop in the chart.( for ex if first i select 30 months and
select range of 30 months it shows s shape but when i enter 20months it shows
S shape till 20months and later it shows drop to zero from 20 to 30 months.