老师好，一直不太理解，我们在画有效前沿时为什么还需要知道协方差，坐标轴分别表示E（Ｒ） 和 标准差 那协方差的作用是什么 为什么要三个东西才能画出有效前沿？

R=P*Q这里的R是什么？是利率嘛？

F=28/4=7这两个数字是怎么来的？

为什么Qd/Px=6.390？

请问，如何通过Div来求DPS？

为什么不选防火墙

The basketball club’s marginal cost is fixed at $2 per visit，边际成本是什么意思？

MARU S.A. de CAT., a Mexican corporation that follows IFRS, has elected to use the revaluation model for its property, plant, and equipment. One of MARU's machines was purchased for 2,500,000 Mexican pesos (MXN) at the beginning of the fiscal year ended 31 March 2010. As of 31 March 2010,the machine has a fair value of MXN 3,000,000. Should MARU show a profit for the revaluation of the machine? 这题的答案，C为什么不对？ B No, because this revaluation is recorded directly in equity. C No, because value increases resulting from revaluation can never be recognised as a profit.

融资成本为什么是百分数的形式，融资成本不是一个金额呢？？

老师，旮差是什么意思？