Lesson 3

Add these two equations to your copy of Formula Sheet.

In the following two Try This activities you will explore strategies used to simplify or solve a problem when a radical is in the denominator.

Try This 2

Consider the fractional radical . What could be done to change the expression so there is no longer a radical in the denominator, without changing the value of the expression?

Try any ideas that occur to you, and then check your ideas using your calculator to ensure the value of the expression is unchanged.

Multiplying the Denominator and the Numerator by a Term to Eliminate the Radical

As you may have discovered in Try This 2, to rationalize the denominator in an expression you can multiply both the denominator and the numerator by the term that will eliminate the radical from the denominator. Watch Rationalizing the Denominator to see this strategy in action.

Self-Check 1

Practise this strategy in Rationalizing Radical Expressions Self-Check.

Try This 3

Consider the fractional radical . What could be done to change the expression so there is no longer a radical in the denominator, without changing the value of the expression?

Try the ideas that occur to you, and check using your calculator to ensure the value of the expression is unchanged.