Surds 1

Question 1

What are the two rules for simplifying square roots?

Answer 1

1) √ab = √a x √b

2) √a/b = √a/√b

Question 2

What is √8 simplified?

Answer 2

√8 = √4 x √2 = 2√2

Question 3

What is √3/25 simplified?

Answer 3

√3/25 = √3/√25 = √3/5

Question 4

What does rationalising the denominator of a fraction mean and how do you do it?

Answer 4

making the denominator a whole number

multiply the top and bottom by the surd in the denominator

Question 5

Rationalise the denominator of 5/3√2

Answer 5

5/3√2 x √2 = 5√2/6

√2 x √2 = 2, so 3 x 2 = 6

Question 6

What does a question asking you to write something in a certain form (e.g. k√3) want you to do?

Answer 6

find integers for all the letters in the expression

e.g. 6√3

Question 7

Show that √45 = 3√5

Answer 7

√45 = √9 x 5 = √9 x √5 = 3√5