1. Leaving Certificate Higher Level
Surds
Leaving Certificate Higher Level

2. Used to rationalise a denominator
Surd Equations

3. Importance of Checking Solutions
© P. Kavanagh, 2006

4. It is vital to check solutions as the squaring method can introduce incorrect solutions.
© P. Kavanagh, 2006
1994 Q1 (a)

5. It is vital to check solutions as the squaring method can introduce incorrect solutions.
© P. Kavanagh, 2006
1994 Q1 (a)

6. Multiply above and below by the conjugate surd.
The bottom line above is the factors of the difference of two squares
Note: With a Casio fx – 83 ES calculator, you can enter this surd using the fraction button.
© P. Kavanagh, 2006
1996 Q1 (a)

7. Multiply above and below by the conjugate surd.
The bottom line above is the factors of the difference of two squares
Note: With a Casio fx – 83 ES calculator, you can enter this surd using the fraction button.
© P. Kavanagh, 2006
1996 Q1 (a)

8. Multiply above and below by the conjugate surd.
© P. Kavanagh, 2006
1999 Q1 (a)

9. Multiply above and below by the conjugate surd.
© P. Kavanagh, 2006
1999 Q1 (a)

10. It is vital to check solutions as the squaring method can introduce incorrect solutions.
© P. Kavanagh, 2006
2002 Q1 (a)

11. It is vital to check solutions as the squaring method can introduce incorrect solutions.
© P. Kavanagh, 2006
2002 Q1 (a)

12. Multiply above and below by the conjugate surd.
Note: With a Casio fx – 83 ES calculator, you can enter this surd using the fraction button.
© P. Kavanagh, 2006
2004 Q1 (a)

13. Multiply above and below by the conjugate surd.
Note: With a Casio fx – 83 ES calculator, you can enter this surd using the fraction button.
© P. Kavanagh, 2006
2004 Q1 (a)