关于图形旋转变换专题的解题方法探究

图形的旋转变换过程大多伴随着其它因素的改变,在旋转变换之后整个数学题目的难度也会由此增大.本文基于初中数学图形旋转变换题解题展开探讨,论述了其在判断图形形状、证明线段数量关系、确定图形位置关系中的应用.帮助学生由旧知识串联起新的知识,通过位置变换后的重新组合做出全等代换.让学生理解清楚各种图形的变换关系,找到正确的解题路径.

探究图形旋转中的变化规律

初中数学课程标准指出：对空间图形学习的评价，应主要考查同学们“空间观念的发展以及合情推理能力的获得”．针对这一要求，近年不少省市中考试卷中加强了图形运动变化(动态几何)类考题设置，其中有一类考题以图形旋转变换为情境背景。

The deformation of Poincar subgroups concerning very special relativity

We investigate here various kinds of semi-product subgroups of Poincar6 group in the scheme of Cohen-Glashow＇s very special relativity along the deformation approach by Gibbons- Gomis-Pope. For each proper Poincar6 subgroup which is a semi-product of proper lorentz group with the spacetime translation group T（4）, we investigate all possible deformations and obtain all the possible natural representations inherited from the 5 - d representation of Poincar6 group. We find from the obtained natural representation that rotation operation may have additional accompanied scale transformation when the original Lorentz subgroup is deformed and the boost operation gets the additional accompanied scale transformation in all the deformation cases. The additional accompanied scale transformation has a strong constrain on the possible invariant metric function of the corresponding geometry and the field theories in the spacetime with the corresponding geometry.