Elementary
Algebra Chapter 8
Roots and Radicals
From
Section 8.1, 8.2, and 8.3
Definition: A number b
is a square root of a
if b2 = a
FACT: Every positive number has two square roots, one that is positive and one that is negative.
Definition: The principal square root of a number is its positive square root. The principale square root of 0 is 0.
FACT: The square root of a negative number is not a real number.
The Pythagorean Theorem: If the length of the hypotenuse of a right triangle is c and the lengths of its legs are a and b, then a2 + b2 = c2
Definition: A number b is a cube root of a if b3 = a
Definition: A number b is the nth root of a if bn = a.