What is the negative square root of 27?

1 Answer
Jul 14, 2015

The negative square root of 27 is -sqrt(27) = -3sqrt(3)

Explanation:

x^2=27 has two solutions, which we call +-sqrt(27)

sqrt(27) denotes the positive square root.

-sqrt(27) is also a square root of 27, which we call the negative square root of 27

If a, b >= 0 then sqrt(ab) = sqrt(a)sqrt(b).

So:

-sqrt(27) = -sqrt(3^2*3)=-sqrt(3^2)sqrt(3) = -3sqrt(3)