Find the Range of the Function
The range of the function
\[ f(x)=\frac{x^2-x}{x^2+2x} \]
is
(a) \(R\)
(b) \(R-\{1\}\)
(c) \(R-\left\{-\frac12,1\right\}\)
(d) none of these
Let
\[ y=\frac{x^2-x}{x^2+2x} \]
Then,
\[ yx^2+2yx=x^2-x \]
\[ (y-1)x^2+(2y+1)x=0 \]
\[ x\left[(y-1)x+(2y+1)\right]=0 \]
Since \(x=0\) is not in domain,
\[ (y-1)x+(2y+1)=0 \]
\[ x=\frac{-(2y+1)}{y-1} \]
For \(x\) to exist,
\[ y\ne1 \]
Also,
\[ x\ne-2 \]
Putting \(x=-2\),
\[ -2=\frac{-(2y+1)}{y-1} \]
\[ 2y-2=2y+1 \]
impossible
So no extra restriction.
Hence,
\[ \boxed{\text{Range}=R-\{1\}} \]
\[ \boxed{\text{Correct Answer: (b)}} \]