Suppose that a is an n dimensional positive--definite real symmetric matrix. answer the following questions prove that the (1,1)-entry (the entry in the first row and first column) of a is a positive real number

Chloe is building a kiosk-based excel application. she wants to make some modifications to the screen elements in order to keep users from being distracted by parts of the application that are irrelevant to her application. she turns to henry for guidance as she knows he built a similar solution earlier this year.chloe has decided to hide the worksheet gridlines and the vertical scroll bar. what does henry tell her to use to do this? a) screen elements dialog boxb) display options dialog boxc) customization dialog boxd) excel options dialog box

List a few alternative options and input and output over the standerd keyboard and monitor. explain their functioning in details.

Which demographic challenge is europe currently experiencing? a. an aging and decreasing population b. a baby boomc. an unequal distribution between males and females d. a large group of teenagers moving through the school system(i chose a but i'm unsure)