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Let A=R−{2}A=R-\{2\} and B=R−{1}B=R-\{1\} and a function f:A→Bf:A\to B defined by f(x)=x−1x−2 ∀x∈Af(x)=\dfrac{x-1}{x-2}\ \forall x\in A, then the function f(x)f(x) is :

Solution

✅ Correct Option: 3

If f(x1)=f(x2)f(x_1)=f(x_2), cross-multiplying reduces to x1=x2x_1=x_2, so ff is injective. Solving y=x−1x−2y=\dfrac{x-1}{x-2} gives x=2y−1y−1x=\dfrac{2y-1}{y-1}, which lies in AA for every y≠1y\neq1, so ff is onto BB. Hence it is bijective.

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