JEE Advanced2011MathematicsFunctionsActual
Let f:(0,1) R be defined by f(x)= b-x 1-b x , where b is a constant such that 0 < b < 1 . Then,
Options
- Af if not invertible on (0,1)
- Bf f⁻¹ on (0,1) and f^ (b)= 1 f^ (0)
- Cf=f⁻¹ on (0,1) and f^ (b)= 1 f^ (0)
- Df⁻¹ is differentiable on (0,1)
Correct answer
A. f if not invertible on (0,1)
Step-by-step solution
Here, f(x)= b-x 1-b x where, 0 0 and b-y 1-b y 1 b (b-1)(y+1) 1-b y < -1 < y < 1 b gathered From Eqs. (i) and (ii), we get y (-1, 1 b ) Codomain Thus, f(x) is not invertible.