# Math

posted by
**Anonymous**
.

I have a couple questions about the sums of geometric series.

One. So the formula for the sum is

t(n)=t(1)[(r^n)-1]

But if my series starts at t(0), can I change the formula to

t(n)=t(0)[(r^n)-1]

?

Two. If, in the series, there is a different pattern in the numerator than in the denominator, how can I solve it?

Such as: [x/2]+[(x^2)/4]+[(x^3)/8]...

Thank you.