ALGEBRA FORMULAS
(a+b)2 = (a2 +b2 +2ab)
(a-b)2 = (a2 + b2 – 2ab)
(a+b)2 + (a-b)2 = 2 (a2 + b2)
(a+b)2 – (a-b)2 = 4ab
(a2-b2) = (a+b) (a-b)
(a+b)3= a3 + b3 + 3ab (a+b)
(a-b)3 = a3 – b3 -3ab (a-b)
(a3+b3) = (a+b) (a2-ab+b2)
(a3-b3) = (a-b) (a2+ab+b2)
Arithmetic progression (A.P)
Series a, a+d, a+2d, a+3d,…….
First term = a
Difference = d
Then
nth term Tn = a + (n-1)d
sum of “n” term Sn = n/2 – (2a + (n-1)d)
sum of n term Sn = n/2 (a+L)
L = last term
Geometric progression (G.P)
a , ar, ar2,…….
First term = a
Difference = r
Then
nth term Tn = arn-1
sum of “n” terms Sn = a(rn – 1 )/ (r – 1)