Week 4- ASMD of Radicals

In Precalc, we have learned about adding, subtracting, multiplying, and dividing radicals. To add or subtract radicals the radicand and the index needs to be the same and only the coeffient will change but if you are multipyling radicals the radicand will multiply with each other, same with the coeffient.

If we have radicals in a fraction we cannot leave the radical in the denominator (and a whole number can’t be negative in the denominator). To get ride of the radical in the denominator we multiply the radical and it’s coeffient(if it has one) with itself and with the numerator. If their is more that one radical we use distribution.

Example: Adding and Subtracting Radicals

6 \sqrt {10} + 5 \sqrt {10} - 10 \sqrt {10}

 

11 \sqrt {10} - 10 \sqrt {10}

 

\sqrt {10}

Example 2: Multiplying and Dividing Radicals

7 \sqrt {10} \cdot 9 \sqrt {14}

 

63 \sqrt {140}

140= 2 \cdot 2 \cdot 5 \cdot 7 (factoring)

63 \cdot 2 \sqrt {5 \cdot 7}

 

126 \sqrt {35}

Example 3: Rationalizing the Denominator

\frac { \sqrt {6}} { \sqrt {3}}

 

\frac { \sqrt {6}} { \sqrt {3}} \cdot \sqrt {3}

 

\frac { \sqrt {18}} { \sqrt {9}}

 

\frac { 3 \sqrt {2}} {3}

 

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