Let A 1 , A 2 , A 3 , … . . be squares such that for each n ⩾ 1 , the length of the side of A n…

Let A1,A2,A3,.. be squares such that for each n1, the length of the side of An equals the length of diagonal of An+1. If the length of A1 is 12 cm, then the smallest value of n for which area of An is less than one, is

Solution

Let an be the side length of An.

So, an=2an+1,a1=12

 an=12×12n-1

Now, an2<11442n-1<1

 2n-1>144

 n-18

 n9

Asked in: JEE Main 2021 (25 Feb Shift 1)

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