Here, d= 2 ,a = 1 So , SN = n/2[a+(n-1)d] => Sn = n/2 [1+(n-1)2] => Sn = n/2 [1+2n-2 ]=> Sn = n/2 [2n-1] => Sn = n^2 -n/2please mark me as BRAINLIEST answer.
Your experience on this site will be improved by allowing cookies. Read Cookie Policy