1 | The application of inversion theory to nonlinear singular systems is an important problem. | |
2 | By using fundamental formula and adaptable estimation of inequality, inverse theorem of mean value ... | |
3 | A necessary and sufficient condition for the direct theorem of the derivatives of positive linear operators is given. | |
4 | This paper will introduce the application of Weda's Theorem and Converse Theorem in analytic geometry. | |
5 | Using the modulus of smoothness and K-functional, direct and inverse theorems of simultaneous approximation for a kind of multivariate trigonometric polynomial operators are established. |