Hi. I posted a correction a while ago, but I still don't see it. Let me try again. I hope this isn't posted twice.

I made a mistake for #2.
When we round down, then the percentage difference between (n+1) and n has not reached our desired percentage change.
Hence, we need to Round Up.
If Chg equals 0.000001
Then

=CEILING((SQRT(Chg^2 + Chg) - Chg)/Chg,1)
Returns 1000.

With n = 1000, then this last value is
=n/(n+1)
=0.999000999000999


For the first question, when n=10, then:
=n*(2+n)
Returns 120.

--
HTH :)
Dana DeLouis


"Sapphy" wrote in message ...

Hi,
I'm trying to work out a way of getting Excel 2003 to answer

y=2i+1 when i=1 initially with a final value of 10.
y=(2x1+1)+(2x2+1)+...+(2x10+1)

I could type it by hand however my next question requires the upper limit n
to be infinity for the eqn

y=1/i(i-1) when i=1 initially and the final value for i=infinity
y=(1/(1(1+1))+(1/2(2+1)+...(1/infinity(infinity+1)

and I eed to find the approximate answer for y when the addition of the
successive terms causes a lass than 0.0001% change in y, as well as the last
value for i when the program stops.

Am utterly stumped! Please help,

Thank you.