answer the questions according to the actural situations：2、[img=424x70]180339ace65cb9f.png[/img]
举一反三
- read the text and answer the questions according to the text：10、她为什么不在宿舍学习？[img=1268x480]180339ad46a06eb.png[/img]
- read the text and answer the questions according to the text：5、我想请玛丽帮我做什么？[img=1336x242]180339ad050248e.png[/img]
- Answer the following questions according to the text1、What is a signal?
- 函数f(x)=[img=15x18]17e0a6f63edb84a.jpg[/img]-5x-4, 则f′(x)=, f′(2)=.
- 设随机变量X 和Y相互独立且都服从正态分布[img=61x27]180387e11b2d7af.png[/img]，而[img=85x23]180387e123ff847.png[/img]和[img=76x23]180387e12c35f4e.png[/img]分别是来自总体X和Y简单随机样本，则统计量[img=136x51]180387e134c69e8.png[/img]服从的分布是( ) A: F(9, 9) B: t(9) C: F(1, 9) D: F(9, 1)