1. 10.5 Use Square Roots to Solve Quadratic Equations

2. Vocabulary If b2 = a then b is a square root of a.
All positive real numbers have two square roots
A positive square root (or principle square root) and a negative square root.
This is written as

3. Vocabulary A square root is written with the radical symbol
The number or expression inside the radical symbol is the radicand.

4. Vocabulary
The square of an integer is called a perfect square.

5. Example 1:

6. Example 2:

7. Example 3:

8. Example 4:

9. You Try:
w2 – 9 = 0
4r2 – 7 = 9
2(y + 4)2 = 18