1819 C2X §3.3

• Wiskunde
• Middelbare school
• havo, vwo
• Leerjaar 2

Which of these does not exist?

1. √​25​​​
2. −√​25​​​
3. √​−25​​​
4. they all exist

Write as short as possible

y=3√​x​​​−6√​2​​​+6√​x​​​−2√​2​​​

1. y=9√​x​​​−4√​2​​​
2. y=9√​x​​​−8√​2​​​
3. y=−3√​x​​​+4√​2​​​
4. Cannot be written any shorter.

Calculate without a calculator

(√​7​​​)​2​​=

Recap

- You cannot take the square root of a negative number

- You can only add and subtract square roots with the same number or variable underneath the square root sign.

- If you square a square root, you get the number underneath the square root sign (if the square root exists).

Multiplying square roots

We've seen that

As a rule we say:

Multiplying square roots

If you multiply different square roots, the following rule applies:

                                                          (if both square roots exist)

Examples:

Multiplying square roots

If you multiply square root numbers, the following rule applies:

                                                                         (if both square roots exist)          

Examples:

Calculation order

When doing calculations with square roots, the Order of Operations applies:

1) Brackets

2) Powers and Roots

3) Multiplication and Division from left to right

4) Adding and Subtracting from left to right

Example:

Homework Tuesday

Make and correct §3.3 (support, standard or challenge)

Which exercises/theories should I discuss on the board?