The formulas of the definite integral calculation in the symmetrical polynomial on odd function and even function is popularixed,and some common results came into being.

This paper explores the odd function and even function\'s property of infinite integral.

Using program of singular function to calculate internal forces of bending pole;

There is a mistake about singular function calculation in the book of "Electric Circuit",which is widely used as the textbook by many colleges.

By means of singular functions, the equations of moment, torque and bending section modulus are given and the general expressions are derived for calculating the torsional stress, angle and deflection of the shaft under complex loads.

Method of establishing the deflection curve of a beam by singularity functions;

Study of the elastic mechanics problem in narrow rectanglar girder by the singularity function;

Based on the improved story analysis model that is used to be widespread, the author sets up a new model with rigid-suspended-joints in core-tube suspended structure, and deduces flank-displacement rigidity matrix used singularity function.

A simplified formula for calcdating the double integral of odd and even functions in the dis-trict of symmetry with examples of application are given.