[3.9] Let fi, f2,., fk: R" → R be convex functions. Consider the function f defined by f(x) = max{fj(x), f2 (x),..., fg (x)}. Show that f is convex. State and prove a similar result for concave functions.

esc You may need to use the appropriate technology to answer this question. The prices (in $) of Rawlston, Inc. stock (y) over a period of 12 days, the number of shares (in 100s) of company's stocks sold (x₁), and the volume of exchange (in millions) on the New York Stock Exchange (x₂) are shown below. ? @ Day 2 1 3 4 5 2 86.00 944 11.50 6 7 8 9 y 10 87.50 951 10.75 84.00 939 11.50 x₁ 83.00 929 12.00 84.50 934 11.75 84.00 936 12.75 82.00 933 80.00 939 78.50 926 x2 Regression 79.00 899 16.75 Excel was used to determine the least squares regression equation. Part of the computer output is shown below. ANOVA Residual 11 77.00 874 17.25 Total 12 77.50 869 17.25 # 13.50 3 14.25 15.25 df SS 10.8542 2 121.0625 60.5312 50.1910 131.9167 f4 $ 4 MS 1.2060 f5 % 5 F f6 4- Significance F 6 f7 0.0000 ♫+ & 7 f8 IAA * fg 8 11 DII hp ( f10 DDI 11 (12 insert prt sc delete backspace home num lock end 1:18 PM 11/29/2022 pg up 00 pg dn

Can you explan it better?  I do not understand.

(2) Chapter 8 X 4