Answer:
(x - 2)² - 30
Step-by-step explanation:
To complete the square
add/subtract ( half the coefficient of the x- term )² to x² - 4x
f(x) = x² + 2(- 2)x + 4 - 4 - 26 = (x - 2)² - 30
Exact Surface Area = 378pi
Approximate Surface Area = 1186.92
The approximate surface area uses pi = 3.14
The units are cm^2 or "square cm".
=========================================================
Work Shown:
SA = surface area of cylinder
SA = 2*pi*r^2 + 2*pi*r*h
SA = 2*pi*7^2 + 2*pi*7*20
SA = 2*pi*49 + 2*pi*140
SA = 2*49*pi + 2*140*pi
SA = 98pi + 280pi
SA = 378pi ..... exact surface area
SA = 378*3.14
SA = 1186.92 ..... approximate surface area
----------
Side note: The diameter 14 cuts in half to get the radius r = 7
Check the attached file for the answer.
Work out the number of hours in 1 year:-
1 year = 365*24 = 8760
So the number dying each hour = 31,000 / 8760 = 3.54
