Solve each of the following in equations and represent the solution set on the number line.
$\frac{|x|-1}{|x|-2} \geq 0, x \in$ R. $-\{-2,2\}$
Given:
$\frac{|x|-1}{|x|-2} \geq 0, x \in$ R. $-\{-2,2\}$
Intervals of $|x|$ :
$x \geq 0,|x|=x$ and $x<0,|x|=-x$
Domain of $\frac{|x|-1}{|x|-2} \geq 0$
$\frac{|x|-1}{|x|-2}$ is not defined for $x=-2$ and $x=2$
Therefore, Domain: x < -2 or -2 < x < 2 or x > 2
Combining intervals with domain:
$x<-2,-2
For $x<-2$ :
$\frac{|x|-1}{|x|-2}=\frac{-x-1}{-x-2}$
$\frac{-x-1}{-x-2} \geq 0$
Signs of $-x-1$ :
$-x-1=0 \rightarrow x=-1$
(Adding 1 to both the sides and then dividing by -1 on both the sides)
$-x-1>0 \rightarrow x<-1$
(Adding 1 to both the sides and then multiplying by -1 on both the sides)
$-x-1<0 \rightarrow x>-1$
(Adding 1 to both the sides and then multiplying by -1 on both the sides)
Signs of $-x-2$ :
$-x-2=0 \rightarrow x=-2$
(Adding 2 to both the sides and then dividing by -1 on both the sides)
$-x-2>0 \rightarrow x<-2$
(Adding 2 to both the sides and then multiplying by -1 on both the sides)
$-x-2<0 \rightarrow x>-2$
(Adding 2 to both the sides and then multiplying by -1 on both the sides)
Intervals satisfying the required condition: ≥ 0
$x<-2$ or $x=-1$ or $x>-1$
Merging overlapping intervals:
$x<-2$ or $x \geq-1$
Combining the intervals:
$x<-2$ or $x \geq-1$ and $x<-2$
Merging overlapping intervals:
$x<-2$
Merging overlapping intervals
$x<-2$
Similarly, for $-2 $\frac{|x|-1}{|x|-2}=\frac{-x-1}{-x-2}$ $\frac{-x-1}{-x-2} \geq 0$ Therefore, Intervals satisfying the required condition: ≥ 0 $x<-2$ or $x=-1$ or $x>-1$ Merging overlapping intervals: $x<-2$ or $x \geq-1$ Combining the intervals: $x<-2$ or $x \geq-1$ and $-2 Merging overlapping intervals: $-1 \leq x<0$ For 0 ≤ x < 2, $\frac{|x|-1}{|x|-2}=\frac{x-1}{x-2}$ $\frac{x-1}{x-2} \geq 0$ Signs of x – 1: $x-1=0 \rightarrow x=1$ (Adding 1 to both the sides) $x-1>0 \rightarrow x>1$ (Adding 1 to both the sides) $x-1<0 \rightarrow x<1$ (Adding 1 to both the sides) Signs of x – 2: $x-2=0 \rightarrow x=2$ (Adding 2 to both the sides) $x-2<0 \rightarrow x<2$ (Adding 2 to both the sides) $x-2>0 \rightarrow x>2$ (Adding 2 to both the sides) At $x=2, \frac{x-1}{x-2}$ is not defined Intervals satisfying the required condition: ≥ 0 $x<1$ or $x=1$ or $x>2$ Merging overlapping intervals: x ≤ 1 or x > 2 Combining the intervals: $x \leq 1$ or $x>2$ and $0 \leq x<2$ Merging overlapping intervals: 0 ≤ x ≤ 1 Similarly, for x > 2: $\frac{|x|-1}{|x|-2}=\frac{x-1}{x-2}$ $\frac{x-1}{x-2} \geq 0$ Therefore, Intervals satisfying the required condition: ≥ 0 $x<1$ or $x=1$ or $x>2$ Merging overlapping intervals: $x \leq 1$ or $x>2$ Combining the intervals: x ≤ 1 or x > 2 and x > 2 Merging overlapping intervals: x > 2 Combining all the intervals: $x<-2$ or $-1 \leq x<0$ or $0 \leq x \leq 1$ or $x>2$ Merging the overlapping intervals: $x<-2$ or $-1 \leq x \leq 1$ or $x>2$ Therefore, $x \in(-\infty,-2) \cup[-1,1] \cup(2, \infty)$