What square root lies between -7 and -6?

Answer 1

-1

Answer 2

-62 = 36 and -72 = 49 so the square roots of all integers 37 to 48 (inclusive) lie between -7 and -6.

Furthermore, the square roots of all real numbers between 36 and 49 (exclusive) also lie between -7 and -6. There are an infinity of such square roots.

Answer 3

The square roots of those numbers which lie between 6² and 7², namely those numbers which lie between 36 and 49.