[Week 3]- Absolute value of a real number

What I have learned:

- What is the absolute value of a real number
- The absolute value of a real number is defined as the principal square root if the square of a number.
- Determine absolute value.
- The relationship with absolute and principal square root.
- √x ² = |x|

Ex. Determine each absolute value.

|4.2|, |-6.1|, |0|, | -3/4 |

4.2, 6.1, 0, 3/4

^{ }

Ex. Evaluate√（3-5） ^{2}

^{ }Use the fact that √（3-5）^{2 } = |x|

√（3-5）^{2 }= |3-5|

^{ } = |-2|

= 2