简介:Fortwotrianglestobecongruent,SAStheoremrequirestwosidesandtheincludedangleofthefirsttriangletobecongruenttothecorrespondingtwosidesandincludedangleofthesecondtriangle.Ifthecongruentanglesarenotbetweenthecorrespondingcongruentsides,thensuchtrianglescouldbedifferent.Itturnsoutthatitispossibletodescribefourcasesinwhichtrianglesarecongruenteventhoughcongruentangles.Fortwotrianglestobecongruent,SAStheoremrequirestwosidesandtheincludedangleofthefirsttriangletobecongruenttothecorrespondingtwosidesandincludedangleofthesecondtriangle.Ifthecongruentanglesarenotbetweenthecorrespondingcongruentsides,thensuchtrianglescouldbedifferent.Itturnsoutthatitispossibletodescribefourcasesinwhichtrianglesarecongruenteventhoughcongruentanglesarenotbetweenthecorrespondingcongruentsides.Suchatheoremcouldbenamed,forexample,SSAtheorem.ManytextsstatethattwotrianglescannotbeshowntobecongruentiftheconditionofSSAexists.However,theauthordescribescasesinwhichsuchtrianglescouldbeprovencongruentwiththeSSAtheorem.Animmediateconsequenceofthisnewunderstandingisthenecessityofrevisingmanyproblemsandanswersinhighschoolandcollege-leveltextsrelatedtocongruenttriangles.arenotbetweenthecorrespondingcongruentsides.Suchatheoremcouldbenamed,forexample,SSAtheorem.Animmediateconsequenceofthisnewunderstandingisthenecessityofrevisingmanyproblemsandanswersinhighschoolandcollege-leveltextsrelatedtocongruenttriangles.
简介:应用SAS/STAT估计非线性回归模型中的参数.首先,通过变量代换,把可以线性化的非线性回归模型化为线性回归模型,并用普通最小二乘法、主成分分析法和偏最小二乘法求模型中的参数和回归模型.其次,通过改良的高斯一牛顿迭代法来估计Logistic模型和Compertz模型中的参数.
简介:摘要:如今有很多分析数据的软件,SAS,SPSS,Python,R,Origin等等,都是为了更加简单的处理、分析数据。我们在实验教学中主要用SAS和R。为了能够让学生加深对多种统计学方法的理解和应用,也为了让学生了解这两种软件,我们对教学中提到的每一种统计方法,都用这两种软件进行操作,对比其优缺点。本文中我们主要用到的统计学方法是主成分分析。