Question

Arithmetic Progression: x, x + y, x + 2y, x + 3y are said to be in A.P. Here x is first term and common difference is y

a) n^th term = x + (n – 1) y

b) Sum of n terms =	n	[2x + (n – 1)y]
	2

3) 1 + 2 + 3 ± - - - - + n =	n(n + 1)
	2

4) (12 + 22 + 32 - - - - + n2) =	n(n + 1) (2n + 1)
	6

5) (13 + 23 + 33 - - - - + n3) =		n(n + 1)		2
		2