Absolute value notation removal

In summary, to eliminate the absolute value sign in the equations |x| < 1 and |x| > 1, we can rewrite |x| < 1 as -1 < x < 1, but for |x| > 1 we cannot simply switch the inequality signs. Instead, we can use the concept of number lines to understand that any number not falling into the first class of |x| > 1 will satisfy the second class of |x| < 1. This means that |x| > 1 can be rewritten as x < -1 OR x > 1.
  • #1
kalpalned
2
0

Homework Statement


Rewrite |x| < 1 and |x| > 1 by eliminating the absolute value sign

Homework Equations


|x| < 1 = -1 < x < 1
|x| > 1 = ?

The Attempt at a Solution


I know that |x| < 1 can be rewritten as -1 < x < 1 but I'm not sure about |x| > 1. Am I right to assume that |x| > 1 = -1 > x > 1?
 
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  • #2
kalpalned said:
|x| > 1 = -1 > x > 1?
Not quite.
kalpalned said:
|x| < 1 = -1 < x < 1
You did this one correctly.
If you can't think about |x|>1 separately,then you can use your previous answer to find this one.

Plot the number line.
Any number on this line will either satisfy:
|x|>1 or |x| <1
There can't be any number not falling into any of these 2 classes.
So,if a number ain't in the first class,it's surely going to be in the second class (neglecting x=1,of course).
Getting what to do now?
 
  • #3
kalpalned said:
Am I right to assume that |x| > 1 = -1 > x > 1?
The way you have this written is that -1 is greater than x AND x is greater than 1. Is that even possible?
Remember when you negate an AND statement, like -1<x<1 which is read -1 is less than x AND x is less than 1, you will get an OR statement.
 
  • #4
Thread closed, as a previous account of the OP's was permanently banned.
 

Related to Absolute value notation removal

What is absolute value notation removal?

Absolute value notation removal refers to the process of simplifying mathematical expressions involving absolute values by eliminating the use of the absolute value notation.

Why do we need to remove absolute value notation?

Removing absolute value notation can help make expressions simpler and easier to work with. It can also help in solving equations and inequalities involving absolute values.

How do you remove absolute value notation?

To remove absolute value notation, you can consider the two cases: when the expression inside the absolute value is positive and when it is negative. For a positive expression, you can simply remove the absolute value bars. For a negative expression, you can change the sign of the expression inside the absolute value and remove the bars.

What are the common mistakes when removing absolute value notation?

One common mistake is forgetting to change the sign of the expression inside the absolute value when it is negative. Another mistake is incorrectly distributing a negative sign to each term inside the absolute value.

Are there any exceptions when removing absolute value notation?

Yes, there are exceptions when removing absolute value notation. For example, if the absolute value is part of a larger expression, you may need to consider the order of operations and simplify the expression first before removing the absolute value. Another exception is when solving equations or inequalities, you may have to introduce a positive and negative solution for the absolute value expression.

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