Chapter 8 - Complex Numbers, Polar Equations, and Parametric Equations - Section 8.4 De Moivre's Theorem: Powers and Roots of Complex Numbers - 8.4 Exercises - Page 378: 59

False The real number 0 only has one real square root.

For every non-zero real number $x$: $x = (\sqrt{x})^2 = (-\sqrt{x})^2$ Thus every real number (except for 0) has two distinct real square roots. However, since 0 has only one square root, and 0 is a real number, it is false to say that every real number must have two distinct real square roots.