an = a+(n-1)d Where an=last term a=first term d=common difference n=number of term Note: last term is denoted by an or l Sn=n/2[2a+(n-1)d Sn=sum of all terms
What are the types of mirror? Concave and convex What are the types of lense? Convex and concave What is the optical centre of lense? It is the centre of a lense What is the principal axis? A line...