# Absolute Value

• Dec 24th 2012, 10:28 PM
srirahulan
Absolute Value
$\mid 2x+5 \mid - \mid x+6 \mid < 2$ Find out the suitable value range for x?
• Dec 25th 2012, 12:23 AM
earboth
Re: Absolute Value
Quote:

Originally Posted by srirahulan
$\mid 2x+5 \mid - \mid x+6 \mid < 2$ Find out the suitable value range for x?

1. Use the definition of the absolute value:

$|2x+5| = \left \lbrace \begin{array}{ccc}2x+5, & 2x+5 \ge 0 \implies & x\ge -\frac52 \\ -(2x+5), & 2x+5 < 0 \implies & x < -\frac52 \end{array} \right.$

$|x+6| = \left \lbrace \begin{array}{ccc}x+6, & x+6 \ge 0 \implies & x\ge -6 \\ -(x+6), & x+6 < 0 \implies & x < -6 \end{array} \right.$

2. You'll get 3 intervals with different inequalities:

$(-\infty, -6)$
$\left[-6, -\frac52 \right)$
$\left[ -\frac52, +\infty \right)$

3. Solve the corresponding 3 inequalities, check the result against the domain.

4. You should come out with $x \in \left(- \frac{13}3 , 3 \right)$

5. Merry Christmas!
• Dec 25th 2012, 12:37 AM
srirahulan
Re: Absolute Value
Thank You and Merry Christmas.