A principal square root is a similar idea to an absolute value. It is only asking for the positive solution to the root of a positive number. A normal square root of a positive number has two solutions (A positive and a negative). read more
The principal square root of a positive number is the positive square root of that number. For example, the principal square root of [math]4[/math] is [math]2[/math], while the principal square root of [math]12[/math] is [math]2\sqrt{3}[/math]. read more
Although the principal square root of a positive number is only one of its two square roots, the designation"the square root" is often used to refer to the principal square root. For positive a, the principal square root can also be written in exponent notation, as a 1/2. read more