If $A = \frac{x-1}{x+1}$, then the value of $A-\frac{1}{A}$ is :
Answer & explanation
Correct answer: option 2
If $A = \frac{x-1}{x+1}$,
then the value of $A-\frac{1}{A}$ = ?
Put the value of x = 2
$A = \frac{2-1}{2+1}$ = \(\frac{1}{3}\)
Now put the value of A into the required equation,
$A-\frac{1}{A}$ = $\frac{1}{3}-\frac{3}{1}$ = $\frac{-8}{3}$
Now check from the options which option is satisfying the value by putting x = 2
If we choose,
$\frac{-4x}{x^2-1}$ = $\frac{-4×2}{2^2-1}$ = $\frac{-8}{3}$ (Satisfied)
So the value of $A-\frac{1}{A}$ = $\frac{-4x}{x^2-1}$