D**u
发帖数: 204 | 1 Let {x_1,...,x_n} be n distinct positive real numbers;
{y_1,...,y_n} be n distinct positive real numbers;
and x_i*x_j is not equal to y_k*y_l for any i,j,k,l.
Question:
(1) you can reorder x_i to z_1,...,z_n, such that
(z_i*_z_j - y_i*y_j)(z_i-z_j)(y_i-y_j) > 0 for any distinct i and j.
(2) Is the reordering in (1) unique |
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