Algebra
Basic formula on Algebra
Arithmetic ProgressionLet us consider a sequence a, a + d, a + 2d, a + 3d, ... where a is the first term of the sequence and d is the common difference.1)  2) nth term of this sequence is given by  such that  3) Sum upto nth term of the sequence is given by  such that  4) When three terms are in A.P., then the middle term is called as Arithmetic Mean of the other two. If a, b, c are in A.P. then  Geometric ProgressionLet us consider a sequence a, ar, ar2, ar3, ...where a is the first term of the sequence and r is the common ratio. 1)  2) nth term of this sequence is given by such that  3) Sum upto nth term of the sequence is given by such that  4) Sum of an infinte Geometric Progression is given by  such that  5) When three terms are in G.P., then the middle term is called as Geometric Mean of the other two. If a, b, c are in G.P. then b = √ac |