Principal Value of a Square Root
A square root of a number is the solution of the equation . It is a number that when multiplied by itself gives you . Every positive number has two square roots , denoted and . The principal square root of is the positive square root, denoted .
The square roots of are and since and .
The principal square root of is .
Find the real roots of the equation .
Therefore, the roots are and .
indicates the principal (or positive) square root so .