fn=(2^2^n) +1 for any nonnegative intcger n 试比较fn与3的大小

题目

fn=(2^2^n) +1 for any nonnegative intcger n 试比较fn与3的大小
a certain company has found that the number of labor hours required to produce x items is directly proportional to the square root of x.if 3 labor hours are required to produce 20 items.how many labor hours are required to produce 40 items

答案

1.when n is a nonnegative interger which means n≥0,2^n≥1suppose 2^n=a,when a≥1,2^a≥2fn=(2^2^n)+1≥2+1=3,thus,fn≥32.h=a根号xwhen 3=a根号20,a=3根号5/10when x=40,h=3根号5/10×根号40=3根号2...