Mark the correct alternative in the following: The first and last term of an A.P. are a and l respectively. If S is the sum of all terms of the A.P. and the common difference is given by , then k =

Question

Philoid · Accepted Answer

Here, a_n=l

∴ a+(n-1)d=l

∴ (n-1)d=l-a

Now, S_n=S

______(1)

Now, given that ______(2)

Comparing (1) and (2) we get

k=2S

Mark the correct alternative in the following:The first and last term of an A.P. are a and l respectively. If S is the sum of all terms of the A.P. and the common difference is given by , then k =

Mark the correct alternative in the following:
The first and last term of an A.P. are a and l respectively. If S is the sum of all terms of the A.P. and the common difference is given by , then k =