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平面直角坐标系是研究数与形的重要工具,是中考的必考知识点,近年来也出现了许多新题型,现请左老师举例说明.一、新规定运算题例1在平面直角坐标系中,对于平面内任一点(m,n),规定以下两种变换:①f(m,n)=(m,-n),如f(2,1)=(2,-1);②g(m,n)=(-m,-n),如g(2,1)=(-2,-1).按照以上变换,有f(g(3,4))=f(-3,-4)=(-3,4),那么g(f(-3,2))等于().A.(3,2)B.(3,-2)C.(-3,2)D.(-3,-2)分析:通过阅读规定的两种变换我们知道,f变换是点的横坐标不变,纵坐标变为
The plane rectangular coordinate system is an important tool for the study of number and shape, and it is a necessary examination point for the Chinese exam. In recent years, many new questions have appeared. Now, please ask the left teacher for an example. First, the new prescription calculation example 1 is in the rectangular coordinate plane. In the system, for any point (m,n) in the plane, the following two types of transformation are specified: 1f(m,n)=(m,-n), such as f(2,1)=(2,-1); 2g (m,n)=(-m,-n), such as g(2,1)=(-2,-1). According to the above transformation, there is f(g(3,4))=f(-3, -4)=(-3,4), then g(f(-3,2)) is equal to ().A.(3,2)B.(3,-2)C.(-3,2)D (-3, -2) analysis: Through reading the prescribed two transformations we know that the f-transform is the point where the abscissa does not change and the ordinate becomes