JEE Main2014MathematicsFunctionsActual
Let f : R → R be defined by f x = x - 1 x + 1 , then f is
Options
- Aone-one but not onto
- Bneither one-one nor onto
- Cboth one-one and onto
- Donto but not one-one
Correct answer
B. neither one-one nor onto
Step-by-step solution
f :   R → R ,   f x = x - 1 x + 1 For x = 0 ,   f x = - 1 And f x = 1 - 1 x 1 + 1 x If x → ± ∞ ,   f x → 1 Thus, the graph of the function f x is given by If a line parallel to the x -axis intersects the graph of a function at more than one point, then the function is many-one. And, it is clear from the graph that, the given function is many-one. Also, the range of the function is [ - 1 ,   1 ) which is not same as the co-domain which is R and if the co-domain o