If a1,a2,a3,a4,a5 are in A.P with common difference ≠0, then find the value ∑i=1ai5 when a3=2.
Finding the value of ∑i=1ai:5
Given a1,a2,a3,a4,a5 are in A.P and a3=2
a+2d=2a=2-2da2=a+d=2-da4=a+3d=2-2d+3d=2+da5=a+4d=2-2d+4d=2+2d∑i=1ai5=a1+a2+a3+a4+a5=2-2d+2-d+2+2+d+2+2d=10
Hence, the value of ∑i=1ai5 is 10..