Chapter 1 - Foundations for Algebra - 1-6 Multiplying and Dividing Real Numbers - Practice and Problem-Solving Exercises - Page 42: 22

-4

We recall that 4 to the second power is 4$\times$ 4, which equals 16. Thus, we find: $\sqrt {16} = \sqrt {4 \times 4} =\sqrt {4^{2}}=4$ However, there is a negative in front of the square root, so we make our answer -4.