Based on the relationship of Jacobi elliptic functions and trigonometric functions,a new method called the trigonometric function transformations methods to solve nonlinear equations is obtained.

Based on the conversion of trigonometric function,a novel real-time algorithm of reactive power similar to that of active power is presented,which reactive power is speed-ily and accurately measured by the voltage,current and frequency.

With the aid of computer algebraic system " Maple" and using the trigonometric function method,the new exact and solitary wave solutions of the combined KdV equation φ t+ α φ φ x+ β φ 2φ x+ γ φ xxx=0 has been obtained.

A new function-transformation method is used and exact travelling wave and solitary wave solutions for Fisher equation and two dimension Burgers-KdV equation are obtained by the function-transformation method.

In the paper,a new function-transformation method is used and two kinds of exact solitary wave solutions for a class of nonlinear wave equations,are obtained by a combination of the function-transformation method and the direct integral method.

In the paper, a new function-transformation method is used and four kinds of explicit exact solitary wave solutions for the nonlinear derivative Schrdinger equation, which have a fifth-order stronger nonlinear term, are obtained by a combination of the function-transformation method and the direct integral method.

Application of the function transform method in solving Bernoulli equation;