What is the formula for calculating the sum of consecutive integers?

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Homework Statement



1+2+3...+n


Homework Equations



count the sum.


The Attempt at a Solution



it's such an easy sum to count but i just want to make sure.

S_{n}=\frac{n}{2}(a_{1}+a_{n})


S_{n}=\frac{n}{2}(1+n)


S_{n}=\frac{n+n^{2}}{2}
 
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Correct. Hope your anxiety is eased
 
Lol its too simple idk why my teacher would give us something so simple I thought there would be a trick or something.
 
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