Week 3 – precalculus 11

Absolute Value:

This week we learned about absolute values of real numbers and how they work in equations. An absolute value is always positive. To find the absolute value of -2 the equation would look like this: $\mid -2 \mid$ and to find the absolute value we make the number +2. The number stays the same but it becomes positive. If the number is already positive it stays that way. You can also have absolute value in an equation. An example would be the following:

$\mid 100 - 32 \mid -2 \mid 5 - 6 \mid$

You then solve inside the lines or absolute value symbols. The absolute value symbols are similar to brackets but are not exactly the same.

$\mid 68 \mid -2 \mid -1 \mid$

Then you find the absolute values (-1 becomes 1) and the lines can become brackets.

$68 - 2 (1)$

2 times 1 is 2

$68 - 2$

Then you take away 2 to get:

$66$

In an equations the | lines act like brackets and once you get the answer you then find the absolute value.

Absolute value can even work in Roots. In cases like this we must use the rule $\sqrt {x^2}$ is equal to $\mid x \mid$

To see this in action it looks like this

$\sqrt {(2 - 4)^2} = \mid 2 - 4 \mid$

Then

$\mid -2 \mid$

Then you find the absolute value.

The root is 2

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Week 3 – precalculus 11

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