Principal roots, rational, irrational numbers || Grade 7 Math || Sir Mathigo
Principal roots and irrational numbers are topics in Grade 7 Math.
Any number, say a, whose nth power (n, a positive integer), is b is called the nth root of b.
The principal nth root of a positive number is the positive nth root.
The principal nth root of a negative number is the negative nth root if n is odd.
If n is even and the number is negative, the principal nth root is not defined.
To determine whether the principal root is a rational or irrational number, determine if the radicand is a perfect nth power or not. If it is, then the root is rational, otherwise,it is irrational.