approximationn.接近；近似；近似值approximation in quadratic norm平方逼近approximation methods in physics物理学中的逼近法approximation measurement method近似测量法approximation of derivative bound导矢界估计approximation to complex functions复变函数逼近approximation of lagrange function拉格朗日函数近似approximation by rational functions有理函数逼近approximation classification quality近似分类质量approximation by elliptic functional椭圆泛函逼近approximation by semiinfinite slopes半无限斜率逼近