考察[0,1]上的函数空间span{x^{1/2},x^{3/2},x^{5/2},...,x^{n-1/2}},定义内积为它们的乘积在[0,1]上的定积分,那么A是基{x^{1/2},x^{3/2},x^{5/2},...,x^{n-1/2}}对应的度量矩阵,所以正定