## sum of first N terms of arithmetic progression

Arithmetic progression (sequence) of terms in which the difference of any term from its preceding term is constant throughout usually written as a,a+d,a+2d,...,a+(n-1)d a being the first term and d the common difference .

## $$\frac{n}{2}[\mathrm{2a}+d(n-1\left)\right]$$

where a = first term d = the common difference n = the total number of terms.

ENTER THE VARIABLES TO BE USED IN THE FORMULA