Positive \({n^{\text{th}}}\) Root

Positive \({n^{\text{th}}}\) Root

Secondary 3

\(3\times 3={{3}^{2}}\)

\(=9\)

\({{3}^{2}}=9\)

\(\therefore \sqrt{9}=3\) (Square Root)

 

\(3\times 3\times 3={{3}^{3}}\)

 

\(=27\)

\({{3}^{3}}=27\)

\(\therefore \sqrt[3]{27}=3\) (Cube Root)

\(3\times 3\times 3\times 3={{3}^{4}}\)

\(=81\)

\({{3}^{4}}=81\)

\(\therefore \sqrt[{}]{81}=3\) (_________ Root)

\(3\times 3\times 3\times 3\times 3={{3}^{5}}\)

\(=243\)

\({{3}^{5}}=243\)

\(\therefore \sqrt[{}]{243}=3\) (_________ Root)

 

\({a = b^n}\)
\({\therefore b =}\)

In general, if \(a\) is a positive number such that \(a={{b}^{n}}\) for some positive real number \(b\) and positive integer \(n\), then \(b\) is the positive n\(^{th}\) root of \(a\) and we write

\(b=\sqrt[n]{a}\)

An expression that involves the radical sign \(\sqrt[n]{\,\,\,\,\,}\) is called the radical expression.

Video Solution:

Video Solution

Video solution locked

A free account saves your progress; this video needs a course plan.

Solution:

Solution locked

680+ questions here come with free worked solutions. A free account saves your questions and progress; this one needs a course plan.

Need help? Join our E-Maths tuition for O-Level success.

Learn more