Arithmetic Progression General Term Formula

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Arithmetic Progression General Term Formula

\[a_n = a_1 + (n-1)d\]

Variables

an = nth term of the sequence
a1 = first term
n = term index
d = common difference

Description

What is this formula?

This formula calculates the nth term of an arithmetic progression using a linear relationship.


When to use it

Use it when you need to find any term in a sequence with constant difference between terms.


Example

Data:

a1 = 3, d = 2, n = 5


Formula:

an = a1 + (n-1)d


Substitution:

a5 = 3 + (5-1)*2


Result:

a5 = 11


Applications

Used in sequences, financial modeling, and discrete mathematics.


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