在求两个变量x和y的线性回归方程过程中, 计算得="25," ="250," ="145," ="1380," 则该回归方程是 .
= .
点P是抛物线上一动点,则点P到y轴距离与点P到点A距离之和的最小值等于 .
已知数列{2n-11},那么的最小值是 .
在△ABC中,若 .
等差数列中, 则的公差为 .