Question

the sum of n terms of ap is​

Answer 1

Answer:

Let a be the first term of the A.P and d be the common difference such that the A.P is

a,a+d,a+2d,a+3d,....,a+(n-1)d.

where n be the number of terms.

Sum of n terms of A.P=n/2[2a+(n-1)d]=n/2[a+l]

where l is the last term , l=a+(n-1)d