n x
MTH 100 n x n x
Radical Expressions n x

Square Roots (n = 2)
• The principal square root of a positive number x is a positive number y such that y 2 = x.
• The square root of a negative number is not a real number (we will discuss imaginary numbers in more detail later).
• For numeric expressions, the square root key on your scientific calculator can be very useful.
• For variable expressions, absolute value bars are used to ensure that the expression remains positive (unless the problem states that all variables are positive).

Cube Roots (n = 3)
• Cube roots are not subject to the same restrictions as square roots. Both the radicand and the result can be negative.
• Some scientific calculators have a cube root key.
• Absolute value bars are not necessary.

Other (larger) roots (n > 4)
• Radicals with an even index are subject to the same rules as square roots.
• Radicals with an odd index are subject to the same rules as cube roots.
• Your scientific calculator has a key equipped to find larger roots.