Simplify Squares Roots (Radicals) That Have Fractions


In these lessons, we will look at some examples of simplifying fractions within a square root (or radical). Some techniques used are: find the square root of the numerator and denominator separately, reduce the fraction and change to improper fraction.




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Related Pages
Rationalize The Denominator
Rationalising Surds

Separate Numerator & Denominator

A. The square root of some fractions can be determined by finding the square root of the numerator and denominator separately.

Example:
\(\sqrt {\frac{{16}}{{25}}} = \frac{{\sqrt {16} }}{{\sqrt {25} }} = \frac{{\sqrt {{4^2}} }}{{\sqrt {{5^2}} }} = \frac{4}{5}\)

For any positive number x and y,
\(\sqrt {\frac{x}{y}} = \frac{{\sqrt x }}{{\sqrt y }}\)

In other words, the square root of a fraction is a fraction of square roots.

Reduce Fraction

B. Some fractions can be reduced to fractions with perfect squares as the numerator and denominator. Then, the square root of the simplified fraction can be determined as shown in the example below.

Example:
\(\sqrt {\frac{{18}}{{50}}} = \sqrt {\frac{9}{{25}}} = \frac{{\sqrt {{3^2}} }}{{\sqrt {{5^2}} }} = \frac{3}{5}\)

Change to Improper Fraction

C. For a mixed number, change it to an improper fraction before finding the square root.

Example:
\(\sqrt {1\frac{{13}}{{36}}} = \sqrt {\frac{{49}}{{36}}} = \frac{{\sqrt {{7^2}} }}{{\sqrt {{6^2}} }} = \frac{7}{6} = 1\frac{1}{6}\)




Example:
Calculate the value of each of the following:
\(\begin{array}{l}{\rm{a)}}\,\,\sqrt {\frac{{25}}{{36}}} \\{\rm{b)}}\,\,\sqrt {\frac{{18}}{{32}}} \\{\rm{c)}}\,\,\sqrt {1\frac{{11}}{{25}}} \end{array}\)

Solution:
Simplify Square Root of Fractions

How to simplify fractions inside a square root?



How to simplify square roots in the denominator of a fraction?

Square Roots of Fractions/Rational Numbers

Finding the square of rational numbers for perfect squares as well as estimating non-perfect squares.

Quotient Rule & Simplifying Square Roots

An introduction to the quotient rule for square roots and radicals and how to use it to simplify expressions containing radicals.

Try the free Mathway calculator and problem solver below to practice various math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.
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