TWO LEVEL SCHWARZ METHODS OF MIXED FINITE ELEMENT APPROXIMATION OF BIHARMONIC PROBLEM

In this paper,the two level additive Schwarz algorithm of mixed finite element.dts-cretization of Inharmonic problem is presented,the rate of convergenece is obtained.Moreover,the two level multiplicative Schwarz algorithm is considered.     

化asinα+bcosα为积的简便公式

全日制十年制学校高中数学第一册中,对于asina+bcosa的化积问题,采用的公式是asina+bcosa=(a~2+b~2)~(1/2) sin(a+ψ),其中ψ由a,b的符号及tgψ=b/a确定。笔者认为,学习了反三角函数之后,应该给出一个更为具体的化积公式。