ALGEBRA 1 HELP -08012017 ????

Question

A student needs to make a circular cardboard piece with an area between 154 square inches and 616 square inches. The function f(r) relates the area of the cardboard piece, in square inches, to the radius r in inches. Which of the following shows a reasonable domain for f(r)?

A. 7 < r < 14
B. 154 < r < 616
C. all positive integers less than 7
D. all positive integers between 14 and 154

Answer 1

πr² = 154            and              πr² = 616

 

r = √(154 / π)      and               r = √(616 / π)

 

r = 7.001                and             r = 14.003

 

 

7.001 ≤ r ≤ 14.003

 

Answer choice is