Question

progression tough questions​

Answer 1

Answer:

Let \displaystyle {a_n}an be a finite arithmetic progression and k be a natural number. \displaystyle a_1=r < 0a1=r<0 and \displaystyle a_k=0ak=0. Find \displaystyle S_{2k-1}S2k−1 (the sum of the first 2k-1 elements of the progression