- #1
Zurtex said:http://mathworld.wolfram.com/GeneratingFunction.html
Hope that helps , looks like it is:
[tex]\frac{x}{1 - x}[/tex]
The sum formula for an expression is a mathematical rule that allows you to find the sum of a series of numbers or terms. It is usually written as Σ (sigma) and followed by the expression to be summed. The general formula is Σn = a + (a + d) + (a + 2d) + ... + (a + (n-1)d), where n is the number of terms, a is the first term, and d is the common difference.
To find the sum formula for an arithmetic sequence, you can use the formula Sn = n/2(2a + (n-1)d), where Sn is the sum of the n terms, a is the first term, and d is the common difference. Alternatively, you can use the general formula for a sum of a series, which is Sn = (n/2)(a + l), where l is the last term.
Yes, there is a sum formula for a geometric sequence, which is Sn = a(r^n - 1)/(r - 1), where Sn is the sum of the n terms, a is the first term, and r is the common ratio. This formula can also be written as Sn = a(1 - r^n)/(1 - r) if the common ratio is less than 1.
The sum of an infinite series can be found by calculating the limit of the partial sums as the number of terms approaches infinity. This is represented by the symbol ∑∞. For example, the infinite series 1 + 1/2 + 1/4 + 1/8 + ... can be written as ∑∞ (1/2)^n, and its sum is equal to 2.
No, the sum formula can only be used for certain types of series, such as arithmetic and geometric series. Other types of series, such as divergent series, do not have a finite sum and cannot be calculated using a sum formula. It is important to identify the type of series before using a sum formula.