If the sum of first p term of an A.P. is ap2 + bp, find its common difference.
Here, sp = ap2 + bp
S1= a + b
S2= ax22 + bx2
=4a + 2b
S2 = a1 + a2
4a + 2b = a1 + a2
A2 = 4a + 2b – (a + b)
A2 = 3a + b
Now, d = common difference = a2 – a1
= 3a + b – (a + b)
= 2a