Combination and summation notation.

In summary, the conversation is discussing the notation \sum (i/k) and how it can be interpreted as (0/k) + (1/k) + (2/k) + ... + (n/k). The speaker also mentions the formula for combinations, n!/(k!(n-k)!), and questions how it can be applied in situations where n is less than k. They conclude that it is not possible to have a negative factorial and n cannot be less than k.
  • #1
EV33
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Homework Statement


I am having trouble reading this notation

[tex]\sum[/tex] (i/k)

The sum is from i=0 to n

I wasn't sure how to write the combination of i,k on the computer so I just wrote it as i/k.


Homework Equations


When I say combination I am talking about this formula n!/(k!(n-k)!)


The Attempt at a Solution



Is this just (0/k)+(1/k)+(2/k)...(n/k)

I am sure I am interpeting it wrong but If I am not what do you do for situations where n is less than k because when you do the combination you get n!/(k!(n-k)!), and I don't think it is possible to do a negative factorial.
 
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  • #2
I don't think 'n' can be less than 'k' for the reason you said.
 

FAQ: Combination and summation notation.

What is combination notation?

Combination notation refers to a mathematical notation used to represent the number of ways to choose a certain number of objects from a larger set, without considering the order in which the objects are chosen.

How is combination notation written?

Combination notation is typically written as nCr, where n represents the total number of objects in the set and r represents the number of objects being chosen.

What is summation notation?

Summation notation is a shorthand way of representing the sum of a series of numbers or terms. It is typically written as Σ, with the numbers or terms being summed written below and the limits of the summation written above and below the Σ symbol.

How is summation notation used?

Summation notation is used to simplify and condense long mathematical expressions involving sums. It is also used to represent sequences and series in mathematics and can be used to find the total area under a curve in calculus.

What is the difference between combination and summation notation?

The main difference between combination and summation notation is that combination notation represents the number of ways to choose a set of objects without considering the order, while summation notation represents the sum of a series of numbers or terms. Additionally, combination notation uses nCr while summation notation uses the Σ symbol to represent the operations.

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