Potential mistake in a textbook? Is $y=x^{1/2}$ the same as $y=±\sqrt{x}$?

Question

So I was consulting a textbook (Stroud, K. A., & Booth, D. J. (2009). Foundation mathematics) for some definitions and noticed the following statement on p. 275:

$y=x^{1/2}$ which is the same as $y=±\sqrt{x}$

I am confused as I have always thought that $f(x)=y=x^{1/2} = \sqrt{x}$. Am I wrong or is that a mistake in the textbook?