The solution set of the equation $|\frac{x+1}{x}|+|x+1|=\frac{(x+1)^2}{|x|}$, is |
$\{x: x ≥0\}$ $\{x:x>0\}∪\{-1\}$ $\{-1,1\}$ $\{x: x ≥1\, or,\, x ≤ -1\}$ |
$\{x:x>0\}∪\{-1\}$ |
We have, $|\frac{x+1}{x}|+|x+1|=\frac{(x+1)^2}{|x|}$ $⇒|\frac{x+1}{x}|+|x+1|=\frac{|x+1|^2}{|x|}$ $⇒|x+1|\left\{\begin{matrix}\frac{1}{|x|}+1-\frac{|x+1|}{|x|}\end{matrix}\right\}=0$ $⇒|x+1|=0$ or, $\frac{1}{|x|}+1=\frac{|x+1|}{|x|}$ $⇒|x+1|=0$ or, $1+|x|=|x+1|$ $⇒x=-1$ or, $1+|x|=|x+1|$ In order to solve the equation $1 +|x|=|x+1|$, we consider the following cases: CASE I When $x <-1$ In this case, we have $|x|=-x$ and $|x+1|=-(x+1)$ $∴1+|x|=|x+1|$ $⇒1-x=-(x+1)$, which is absurd. CASE II When $-1≤x<0$ In this case, we have $|x|=-x$ and $|x+1|=x+1$ $∴1+|x|=|x+1|⇒1-x=x+1⇒x=0$ But, $-1≤x<0$ So, there is no solution in this case. CASE III When x ≥ 0. In this case, we have $|x|=x$ and $|x+1|=x+1$ $∴1+|x|=|x+1|$ $⇒1+x=x+1$, which is true for all x. Clearly, the given equation is meaningful for x ≠ 0. Hence, the solution set of the given equation is $\{x:x>0\}∪\{-1\}$. |