In calculating , we have the liberty to choose:

(1) The mode of partition is one wherein the sub intervals are of the same length, say Dx Clearly, the points of division form an A.P.

Note : The area in the question is that of trapezium ABCD in figure by usual formula,

This area is

Index

7.1 Definition
7.2 Definite integral as on an area under curve
7.3 Working rule for evaluation of a definite integral as a limit of a sun
7.4 Fundamental theorem of integrated calculus
7.5 Properties of definite integrals
7.6 Evaluation of definite integral
7.7 Reduction formulas