What is the square root of 64?

Its 8 or -8.

#### Explanation:

8 x 8 = 64.The principal square root of 64 is:%sqrt(64) = 8%The other (non-principal) square root is:-sqrt(64) = -8

#### Explanation:

64 has two square roots, namely 8 and -8, since:8^2 = (-8)^2 = 64When we say the square root, what is usually intended is the principal square root, which in the case of the Real square root of a positive number is the positive one.Any non-zero number n has two square roots. In order to distinguish between them, we call one the principal square root, which in the case of n > 0 means the positive one.color(white)()**Complex footnote**If then it has two Complex non-Real square roots:+-i sqrt(-n)In this case we call i sqrt(-n) the principal square root and -i sqrt(-n) the non-principal one.For example:sqrt(-64) = 8i is the principal square root.-sqrt(-64) = -8i is the other square root.Note that 8i is not positive. Unlike Real numbers, Complex numbers are not ordered, but for pure imaginary square roots we choose the one with the positive imaginary part and call it principal.

The sequre root of 64 is +_8.