Between what integers does sqrt132132 lie?

2 Answers
Jan 13, 2017

Between 11 and 12
Please remember that 11^2 = 121 and 12^2 = 144112=121and122=144
132 is between those two squares.

Jan 13, 2017

1111 and 1212

Explanation:

Note that:

132 = 11xx12132=11×12

and:

11xx11 < 11xx12 < 12xx1211×11<11×12<12×12

Hence:

sqrt(11xx11) < sqrt(11xx12) < sqrt(12xx12)11×11<11×12<12×12

That is:

11 < sqrt(132) < 1211<132<12

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Footnote

Since 132 = 11xx12132=11×12 is of the form n(n+1)n(n+1) (with n=11n=11), its square root has a simple continued fraction form:

sqrt(132) = [11;bar(2,22)] = 11+1/(2+1/(22+1/(2+1/(22+1/(2+1/(22+1/(2+...)))))))

In general:

sqrt(n(n+1)) = [n;bar(2, 2n)] = n+1/(2+1/(2n+1/(2+1/(2n+1/(2+1/(2n+1/(2+...)))))))