From the definition of the admission transform and admission single parameter group,it s investigated the relation between first order obvious differential equation and integral factor , this result provides more broad method for seeking the integral.

The solution of first order ordinary differential equation with the integral factor of a product form

Existence and application of two integrating factors on first order ordinary differential equation

Essentially,the opposite reaction kinetics process is a process of resolving the first order ordinary differential equation.

In this article, a general soution is given to the inteqral divisor of the differential equation of first order by applying the necessary and sufficient condition of the total differential equatio

It is shown that the common method of integrating factor of differential equation of first order is given.

In this paper,We make an elementary transfomation to some special Riccati equations,get the second order differential equation or first order differential equations,after that get the special solution of the Riccati equation with the help of special solution of the second order differential equation or first order differential equations,or formula method and observation trial method.

In this paper,we discuss Osgood condition further,then we have the simplified method to judge the unicity of zero solution about first order differential equation,this bring large convenient to judge the unicity of zero solution about first order differential equation.

Regarding seeking solution of three kinds of first order differential equations,usually the reference book introduces some methods of looking for integral factor ,then transforms integral factor into full differential equation ,finally through which the solutien is found.